diff --git a/build.gradle b/build.gradle
index f64c7edbdc..02ea4c9871 100644
--- a/build.gradle
+++ b/build.gradle
@@ -232,10 +232,19 @@ configurations {
 check.dependsOn jacocoTestReport
 
 // TODO: fix code style in main and test source code
+subprojects {
+    apply plugin: 'checkstyle'
+    checkstyle {
+        configFile rootProject.file("config/checkstyle/google_checks.xml")
+        toolVersion "8.20"
+        configProperties = [
+                "org.checkstyle.google.suppressionfilter.config": rootProject.file("config/checkstyle/suppressions.xml")]
+        ignoreFailures = false
+    }
+}
 checkstyle {
     configFile file("config/checkstyle/checkstyle.xml")
 }
-
 checkstyleMain.ignoreFailures = false
 checkstyleTest.ignoreFailures = true
 
diff --git a/common/build.gradle b/common/build.gradle
index 59ba428729..0849fae080 100644
--- a/common/build.gradle
+++ b/common/build.gradle
@@ -9,7 +9,7 @@ repositories {
 
 dependencies {
     compile "org.antlr:antlr4-runtime:4.7.1"
-    compile group: 'com.google.guava', name: 'guava', version:'23.0'
+    compile group: 'com.google.guava', name: 'guava', version: '23.0'
 
     testCompile group: 'junit', name: 'junit', version: '4.12'
 }
diff --git a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/CaseInsensitiveCharStream.java b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/CaseInsensitiveCharStream.java
index 7ab5a15ac0..f251076d6c 100644
--- a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/CaseInsensitiveCharStream.java
+++ b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/CaseInsensitiveCharStream.java
@@ -20,63 +20,64 @@
 import org.antlr.v4.runtime.misc.Interval;
 
 /**
- * Custom stream to convert character to upper case for case insensitive grammar before sending to lexer.
+ * Custom stream to convert character to upper case for case insensitive grammar before sending to
+ * lexer.
  */
 public class CaseInsensitiveCharStream implements CharStream {
 
-    /** Character stream */
-    private final CharStream charStream;
+  /** Character stream. */
+  private final CharStream charStream;
 
-    public CaseInsensitiveCharStream(String sql) {
-        this.charStream = CharStreams.fromString(sql);
-    }
+  public CaseInsensitiveCharStream(String sql) {
+    this.charStream = CharStreams.fromString(sql);
+  }
 
-    @Override
-    public String getText(Interval interval) {
-        return charStream.getText(interval);
-    }
+  @Override
+  public String getText(Interval interval) {
+    return charStream.getText(interval);
+  }
 
-    @Override
-    public void consume() {
-        charStream.consume();
-    }
+  @Override
+  public void consume() {
+    charStream.consume();
+  }
 
-    @Override
-    public int LA(int i) {
-        int c = charStream.LA(i);
-        if (c <= 0) {
-            return c;
-        }
-        return Character.toUpperCase(c);
+  @Override
+  public int LA(int i) {
+    int c = charStream.LA(i);
+    if (c <= 0) {
+      return c;
     }
+    return Character.toUpperCase(c);
+  }
 
-    @Override
-    public int mark() {
-        return charStream.mark();
-    }
+  @Override
+  public int mark() {
+    return charStream.mark();
+  }
 
-    @Override
-    public void release(int marker) {
-        charStream.release(marker);
-    }
+  @Override
+  public void release(int marker) {
+    charStream.release(marker);
+  }
 
-    @Override
-    public int index() {
-        return charStream.index();
-    }
+  @Override
+  public int index() {
+    return charStream.index();
+  }
 
-    @Override
-    public void seek(int index) {
-        charStream.seek(index);
-    }
+  @Override
+  public void seek(int index) {
+    charStream.seek(index);
+  }
 
-    @Override
-    public int size() {
-        return charStream.size();
-    }
+  @Override
+  public int size() {
+    return charStream.size();
+  }
 
-    @Override
-    public String getSourceName() {
-        return charStream.getSourceName();
-    }
+  @Override
+  public String getSourceName() {
+    return charStream.getSourceName();
+  }
 }
diff --git a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/SyntaxAnalysisErrorListener.java b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/SyntaxAnalysisErrorListener.java
index 6f7c8a5d1a..8bd7731ab0 100644
--- a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/SyntaxAnalysisErrorListener.java
+++ b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/antlr/SyntaxAnalysisErrorListener.java
@@ -15,6 +15,7 @@
 
 package com.amazon.opendistroforelasticsearch.sql.common.antlr;
 
+import java.util.Locale;
 import org.antlr.v4.runtime.BaseErrorListener;
 import org.antlr.v4.runtime.CommonTokenStream;
 import org.antlr.v4.runtime.RecognitionException;
@@ -22,53 +23,55 @@
 import org.antlr.v4.runtime.Token;
 import org.antlr.v4.runtime.misc.IntervalSet;
 
-import java.util.Locale;
-
 /**
- * Syntax analysis error listener that handles any syntax error by throwing exception with useful information.
+ * Syntax analysis error listener that handles any syntax error by throwing exception with useful
+ * information.
  */
 public class SyntaxAnalysisErrorListener extends BaseErrorListener {
 
-    @Override
-    public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol,
-                            int line, int charPositionInLine, String msg,
-                            RecognitionException e) {
+  @Override
+  public void syntaxError(
+      Recognizer<?, ?> recognizer,
+      Object offendingSymbol,
+      int line,
+      int charPositionInLine,
+      String msg,
+      RecognitionException e) {
 
-        CommonTokenStream tokens = (CommonTokenStream) recognizer.getInputStream();
-        Token offendingToken = (Token) offendingSymbol;
-        String query = tokens.getText();
+    CommonTokenStream tokens = (CommonTokenStream) recognizer.getInputStream();
+    Token offendingToken = (Token) offendingSymbol;
+    String query = tokens.getText();
 
-        throw new RuntimeException(
-                String.format(Locale.ROOT,
-                        "Failed to parse query due to offending symbol [%s] at: '%s' <--- HERE... More details: %s",
-                        getOffendingText(offendingToken),
-                        truncateQueryAtOffendingToken(query, offendingToken),
-                        getDetails(recognizer, msg, e)
-                )
-        );
-    }
+    throw new RuntimeException(
+        String.format(
+            Locale.ROOT,
+            "Failed to parse query due to offending symbol [%s] "
+                + "at: '%s' <--- HERE... More details: %s",
+            getOffendingText(offendingToken),
+            truncateQueryAtOffendingToken(query, offendingToken),
+            getDetails(recognizer, msg, e)));
+  }
 
-    private String getOffendingText(Token offendingToken) {
-        return offendingToken.getText();
-    }
+  private String getOffendingText(Token offendingToken) {
+    return offendingToken.getText();
+  }
 
-    private String truncateQueryAtOffendingToken(String query, Token offendingToken) {
-        return query.substring(0, offendingToken.getStopIndex() + 1);
-    }
+  private String truncateQueryAtOffendingToken(String query, Token offendingToken) {
+    return query.substring(0, offendingToken.getStopIndex() + 1);
+  }
 
-    /**
-     * As official JavaDoc says, e=null means parser was able to recover from the error.
-     * In other words, "msg" argument includes the information we want.
-     */
-    private String getDetails(Recognizer<?, ?> recognizer, String msg, RecognitionException e) {
-        String details;
-        if (e == null) {
-            details = msg;
-        } else {
-            IntervalSet followSet = e.getExpectedTokens();
-            details = "Expecting tokens in " + followSet.toString(recognizer.getVocabulary());
-        }
-        return details;
+  /**
+   * As official JavaDoc says, e=null means parser was able to recover from the error. In other
+   * words, "msg" argument includes the information we want.
+   */
+  private String getDetails(Recognizer<?, ?> recognizer, String msg, RecognitionException e) {
+    String details;
+    if (e == null) {
+      details = msg;
+    } else {
+      IntervalSet followSet = e.getExpectedTokens();
+      details = "Expecting tokens in " + followSet.toString(recognizer.getVocabulary());
     }
-
+    return details;
+  }
 }
diff --git a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/response/ResponseListener.java b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/response/ResponseListener.java
index 2ebbdd0fac..e786de0bf4 100644
--- a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/response/ResponseListener.java
+++ b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/response/ResponseListener.java
@@ -17,23 +17,24 @@
 package com.amazon.opendistroforelasticsearch.sql.common.response;
 
 /**
- * Response listener for response post-processing callback.
- * This is necessary because execution engine may schedule and execute in different thread.
+ * Response listener for response post-processing callback. This is necessary because execution
+ * engine may schedule and execute in different thread.
  *
- * @param <Response>    response class
+ * @param <R> response class
  */
-public interface ResponseListener<Response> {
+public interface ResponseListener<R> {
 
-    /**
-     * Handle successful response.
-     * @param response  successful response
-     */
-    void onResponse(Response response);
-
-    /**
-     * Handle failed response.
-     * @param e     exception captured
-     */
-    void onFailure(Exception e);
+  /**
+   * Handle successful response.
+   *
+   * @param response successful response
+   */
+  void onResponse(R response);
 
+  /**
+   * Handle failed response.
+   *
+   * @param e exception captured
+   */
+  void onFailure(Exception e);
 }
diff --git a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/utils/StringUtils.java b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/utils/StringUtils.java
index 75d590878e..1df4b26758 100644
--- a/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/utils/StringUtils.java
+++ b/common/src/main/java/com/amazon/opendistroforelasticsearch/sql/common/utils/StringUtils.java
@@ -18,27 +18,35 @@
 import com.google.common.base.Strings;
 
 public class StringUtils {
-    /**
-     * @param text string
-     * @param mark quotation mark
-     * @return An unquoted string whose outer pair of (single/double/back-tick) quotes have been removed
-     */
-    public static String unquoteIdentifier(String text, String mark) {
-        if (isQuoted(text, mark)) {
-            return text.substring(mark.length(), text.length() - mark.length());
-        }
-        return text;
+  /**
+   * Unquote Identifier with mark.
+   * @param text string
+   * @param mark quotation mark
+   * @return An unquoted string whose outer pair of (single/double/back-tick) quotes have been
+   *     removed
+   */
+  public static String unquoteIdentifier(String text, String mark) {
+    if (isQuoted(text, mark)) {
+      return text.substring(mark.length(), text.length() - mark.length());
     }
+    return text;
+  }
 
-    public static String unquoteIdentifier(String text) {
-        if (isQuoted(text, "\"") || isQuoted(text, "'") || isQuoted(text, "`")) {
-            return text.substring(1, text.length() - 1);
-        } else {
-            return text;
-        }
+  /**
+   * Unquote Identifier which has " or ' or ` as mark.
+   * @param text string
+   * @return An unquoted string whose outer pair of (single/double/back-tick) quotes have been
+   *     removed
+   */
+  public static String unquoteIdentifier(String text) {
+    if (isQuoted(text, "\"") || isQuoted(text, "'") || isQuoted(text, "`")) {
+      return text.substring(1, text.length() - 1);
+    } else {
+      return text;
     }
+  }
 
-    private static boolean isQuoted(String text, String mark) {
-        return !Strings.isNullOrEmpty(text) && text.startsWith(mark) && text.endsWith(mark);
-    }
+  private static boolean isQuoted(String text, String mark) {
+    return !Strings.isNullOrEmpty(text) && text.startsWith(mark) && text.endsWith(mark);
+  }
 }
diff --git a/config/checkstyle/google_checks.xml b/config/checkstyle/google_checks.xml
new file mode 100644
index 0000000000..4dfcaf39cb
--- /dev/null
+++ b/config/checkstyle/google_checks.xml
@@ -0,0 +1,264 @@
+<?xml version="1.0"?>
+<!DOCTYPE module PUBLIC
+        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+        "https://checkstyle.org/dtds/configuration_1_3.dtd">
+
+<!--
+    Checkstyle configuration that checks the Google coding conventions from Google Java Style
+    that can be found at https://google.github.io/styleguide/javaguide.html.
+    Checkstyle is very configurable. Be sure to read the documentation at
+    http://checkstyle.sf.net (or in your downloaded distribution).
+    To completely disable a check, just comment it out or delete it from the file.
+    Authors: Max Vetrenko, Ruslan Diachenko, Roman Ivanov.
+ -->
+
+<module name = "Checker">
+  <property name="charset" value="UTF-8"/>
+
+  <property name="severity" value="error"/>
+
+  <property name="fileExtensions" value="java, properties, xml"/>
+  <!-- Excludes all 'module-info.java' files              -->
+  <!-- See https://checkstyle.org/config_filefilters.html -->
+  <module name="BeforeExecutionExclusionFileFilter">
+    <property name="fileNamePattern" value="module\-info\.java$"/>
+  </module>
+  <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
+  <module name="SuppressionFilter">
+    <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
+              default="checkstyle-suppressions.xml" />
+    <property name="optional" value="true"/>
+  </module>
+  <!-- Checks for whitespace                               -->
+  <!-- See http://checkstyle.sf.net/config_whitespace.html -->
+  <module name="FileTabCharacter">
+    <property name="eachLine" value="true"/>
+  </module>
+
+  <module name="TreeWalker">
+    <module name="OuterTypeFilename"/>
+    <module name="IllegalTokenText">
+      <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
+      <property name="format"
+                value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
+      <property name="message"
+                value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
+    </module>
+    <module name="AvoidEscapedUnicodeCharacters">
+      <property name="allowEscapesForControlCharacters" value="true"/>
+      <property name="allowByTailComment" value="true"/>
+      <property name="allowNonPrintableEscapes" value="true"/>
+    </module>
+    <module name="LineLength">
+      <property name="max" value="100"/>
+      <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
+    </module>
+    <module name="AvoidStarImport"/>
+    <module name="OneTopLevelClass"/>
+    <module name="NoLineWrap"/>
+    <module name="EmptyBlock">
+      <property name="option" value="TEXT"/>
+      <property name="tokens"
+                value="LITERAL_TRY, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE, LITERAL_SWITCH"/>
+    </module>
+    <module name="NeedBraces"/>
+    <module name="LeftCurly"/>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlySame"/>
+      <property name="tokens"
+                value="LITERAL_TRY, LITERAL_CATCH, LITERAL_FINALLY, LITERAL_IF, LITERAL_ELSE,
+                    LITERAL_DO"/>
+    </module>
+    <module name="RightCurly">
+      <property name="id" value="RightCurlyAlone"/>
+      <property name="option" value="alone"/>
+      <property name="tokens"
+                value="CLASS_DEF, METHOD_DEF, CTOR_DEF, LITERAL_FOR, LITERAL_WHILE, STATIC_INIT,
+                    INSTANCE_INIT"/>
+    </module>
+    <module name="WhitespaceAround">
+      <property name="allowEmptyConstructors" value="true"/>
+      <property name="allowEmptyLambdas" value="true"/>
+      <property name="allowEmptyMethods" value="true"/>
+      <property name="allowEmptyTypes" value="true"/>
+      <property name="allowEmptyLoops" value="true"/>
+      <message key="ws.notFollowed"
+               value="WhitespaceAround: ''{0}'' is not followed by whitespace. Empty blocks may only be represented as '{}' when not part of a multi-block statement (4.1.3)"/>
+      <message key="ws.notPreceded"
+               value="WhitespaceAround: ''{0}'' is not preceded with whitespace."/>
+    </module>
+    <module name="OneStatementPerLine"/>
+    <module name="MultipleVariableDeclarations"/>
+    <module name="ArrayTypeStyle"/>
+    <module name="MissingSwitchDefault"/>
+    <module name="FallThrough"/>
+    <module name="UpperEll"/>
+    <module name="ModifierOrder"/>
+    <module name="EmptyLineSeparator">
+      <property name="allowNoEmptyLineBetweenFields" value="true"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapDot"/>
+      <property name="tokens" value="DOT"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapComma"/>
+      <property name="tokens" value="COMMA"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ELLIPSIS is EOL until https://github.com/google/styleguide/issues/258 -->
+      <property name="id" value="SeparatorWrapEllipsis"/>
+      <property name="tokens" value="ELLIPSIS"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <!-- ARRAY_DECLARATOR is EOL until https://github.com/google/styleguide/issues/259 -->
+      <property name="id" value="SeparatorWrapArrayDeclarator"/>
+      <property name="tokens" value="ARRAY_DECLARATOR"/>
+      <property name="option" value="EOL"/>
+    </module>
+    <module name="SeparatorWrap">
+      <property name="id" value="SeparatorWrapMethodRef"/>
+      <property name="tokens" value="METHOD_REF"/>
+      <property name="option" value="nl"/>
+    </module>
+    <module name="PackageName">
+      <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+      <message key="name.invalidPattern"
+               value="Package name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="TypeName">
+      <message key="name.invalidPattern"
+               value="Type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="MemberName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+      <message key="name.invalidPattern"
+               value="Member name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="ParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+               value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="LambdaParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+               value="Lambda parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="CatchParameterName">
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+               value="Catch parameter name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="LocalVariableName">
+      <property name="tokens" value="VARIABLE_DEF"/>
+      <property name="format" value="^[a-z]([a-z0-9][a-zA-Z0-9]*)?$"/>
+      <message key="name.invalidPattern"
+               value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="ClassTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+               value="Class type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="MethodTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+               value="Method type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="InterfaceTypeParameterName">
+      <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+      <message key="name.invalidPattern"
+               value="Interface type name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="NoFinalizer"/>
+    <module name="GenericWhitespace">
+      <message key="ws.followed"
+               value="GenericWhitespace ''{0}'' is followed by whitespace."/>
+      <message key="ws.preceded"
+               value="GenericWhitespace ''{0}'' is preceded with whitespace."/>
+      <message key="ws.illegalFollow"
+               value="GenericWhitespace ''{0}'' should followed by whitespace."/>
+      <message key="ws.notPreceded"
+               value="GenericWhitespace ''{0}'' is not preceded with whitespace."/>
+    </module>
+    <module name="Indentation">
+      <property name="basicOffset" value="2"/>
+      <property name="braceAdjustment" value="0"/>
+      <property name="caseIndent" value="2"/>
+      <property name="throwsIndent" value="4"/>
+      <property name="lineWrappingIndentation" value="4"/>
+      <property name="arrayInitIndent" value="2"/>
+    </module>
+    <module name="AbbreviationAsWordInName">
+      <property name="ignoreFinal" value="false"/>
+      <property name="allowedAbbreviationLength" value="9"/>
+    </module>
+    <module name="OverloadMethodsDeclarationOrder"/>
+    <module name="VariableDeclarationUsageDistance"/>
+    <module name="CustomImportOrder">
+      <property name="sortImportsInGroupAlphabetically" value="true"/>
+      <property name="separateLineBetweenGroups" value="true"/>
+      <property name="customImportOrderRules" value="STATIC###THIRD_PARTY_PACKAGE"/>
+    </module>
+    <module name="MethodParamPad"/>
+    <module name="NoWhitespaceBefore">
+      <property name="tokens"
+                value="COMMA, SEMI, POST_INC, POST_DEC, DOT, ELLIPSIS, METHOD_REF"/>
+      <property name="allowLineBreaks" value="true"/>
+    </module>
+    <module name="ParenPad"/>
+    <module name="OperatorWrap">
+      <property name="option" value="NL"/>
+      <property name="tokens"
+                value="BAND, BOR, BSR, BXOR, DIV, EQUAL, GE, GT, LAND, LE, LITERAL_INSTANCEOF, LOR,
+                    LT, MINUS, MOD, NOT_EQUAL, PLUS, QUESTION, SL, SR, STAR, METHOD_REF "/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationMostCases"/>
+      <property name="tokens"
+                value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF"/>
+    </module>
+    <module name="AnnotationLocation">
+      <property name="id" value="AnnotationLocationVariables"/>
+      <property name="tokens" value="VARIABLE_DEF"/>
+      <property name="allowSamelineMultipleAnnotations" value="true"/>
+    </module>
+    <module name="NonEmptyAtclauseDescription"/>
+    <module name="JavadocTagContinuationIndentation"/>
+    <module name="SummaryJavadoc">
+      <property name="forbiddenSummaryFragments"
+                value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+    </module>
+    <module name="JavadocParagraph"/>
+    <module name="AtclauseOrder">
+      <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
+      <property name="target"
+                value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
+    </module>
+    <module name="JavadocMethod">
+      <property name="scope" value="public"/>
+      <property name="allowMissingParamTags" value="true"/>
+      <property name="allowMissingThrowsTags" value="true"/>
+      <property name="allowMissingReturnTag" value="true"/>
+      <property name="minLineCount" value="2"/>
+      <property name="allowedAnnotations" value="Override, Test"/>
+      <property name="allowThrowsTagsForSubclasses" value="true"/>
+    </module>
+    <module name="MethodName">
+      <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9_]*$"/>
+      <message key="name.invalidPattern"
+               value="Method name ''{0}'' must match pattern ''{1}''."/>
+    </module>
+    <module name="SingleLineJavadoc">
+      <property name="ignoreInlineTags" value="false"/>
+    </module>
+    <module name="EmptyCatchBlock">
+      <property name="exceptionVariableName" value="expected"/>
+    </module>
+    <module name="CommentsIndentation"/>
+  </module>
+</module>
diff --git a/config/checkstyle/suppressions.xml b/config/checkstyle/suppressions.xml
index ec4edb849d..15f02089e2 100644
--- a/config/checkstyle/suppressions.xml
+++ b/config/checkstyle/suppressions.xml
@@ -6,5 +6,6 @@
 <suppressions>
 
     <suppress files="com[\\/]amazon[\\/]opendistroforelasticsearch[\\/]sql[\\/]antlr[\\/]parser" checks=".*"/>
+    <suppress files="com[\\/]amazon[\\/]opendistroforelasticsearch[\\/]sql[\\/]ppl[\\/]antlr[\\/]parser" checks=".*"/>
 
 </suppressions>
\ No newline at end of file
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContext.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContext.java
index f9d51b32c8..b04c88ef2d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContext.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContext.java
@@ -21,41 +21,45 @@
  * The context used for Analyzer.
  */
 public class AnalysisContext {
-    /** Environment stack for symbol scope management */
-    private TypeEnvironment environment;
-
-    public AnalysisContext() {
-        this.environment = new TypeEnvironment(null);
-    }
-
-    public AnalysisContext(TypeEnvironment environment) {
-        this.environment = environment;
-    }
-
-    /**
-     * Push a new environment
-     */
-    public void push() {
-        environment = new TypeEnvironment(environment);
-    }
-
-    /**
-     * Return current environment
-     * @return  current environment
-     */
-    public TypeEnvironment peek() {
-        return environment;
-    }
-
-    /**
-     * Pop up current environment from environment chain
-     * @return  current environment (before pop)
-     */
-    public TypeEnvironment pop() {
-        Objects.requireNonNull(environment, "Fail to pop context due to no environment present");
-
-        TypeEnvironment curEnv = environment;
-        environment = curEnv.getParent();
-        return curEnv;
-    }
+  /**
+   * Environment stack for symbol scope management.
+   */
+  private TypeEnvironment environment;
+
+  public AnalysisContext() {
+    this.environment = new TypeEnvironment(null);
+  }
+
+  public AnalysisContext(TypeEnvironment environment) {
+    this.environment = environment;
+  }
+
+  /**
+   * Push a new environment.
+   */
+  public void push() {
+    environment = new TypeEnvironment(environment);
+  }
+
+  /**
+   * Return current environment.
+   *
+   * @return current environment
+   */
+  public TypeEnvironment peek() {
+    return environment;
+  }
+
+  /**
+   * Pop up current environment from environment chain.
+   *
+   * @return current environment (before pop)
+   */
+  public TypeEnvironment pop() {
+    Objects.requireNonNull(environment, "Fail to pop context due to no environment present");
+
+    TypeEnvironment curEnv = environment;
+    environment = curEnv.getParent();
+    return curEnv;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/Analyzer.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/Analyzer.java
index 7b283f57b2..23afac1c4b 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/Analyzer.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/Analyzer.java
@@ -61,7 +61,7 @@
 
 /**
  * Analyze the {@link UnresolvedPlan} in the {@link AnalysisContext} to construct the {@link
- * LogicalPlan}
+ * LogicalPlan}.
  */
 @RequiredArgsConstructor
 public class Analyzer extends AbstractNodeVisitor<LogicalPlan, AnalysisContext> {
@@ -88,7 +88,9 @@ public LogicalPlan visitFilter(Filter node, AnalysisContext context) {
     return new LogicalFilter(child, condition);
   }
 
-  /** Build {@link LogicalRename} */
+  /**
+   * Build {@link LogicalRename}.
+   */
   @Override
   public LogicalPlan visitRename(Rename node, AnalysisContext context) {
     LogicalPlan child = node.getChild().get(0).accept(this, context);
@@ -111,18 +113,20 @@ public LogicalPlan visitRename(Rename node, AnalysisContext context) {
     return new LogicalRename(child, renameMapBuilder.build());
   }
 
-  /** Build {@link LogicalAggregation} */
+  /**
+   * Build {@link LogicalAggregation}.
+   */
   @Override
   public LogicalPlan visitAggregation(Aggregation node, AnalysisContext context) {
     LogicalPlan child = node.getChild().get(0).accept(this, context);
     ImmutableList.Builder<Aggregator> aggregatorBuilder = new ImmutableList.Builder<>();
-    for (UnresolvedExpression uExpr : node.getAggExprList()) {
-      aggregatorBuilder.add((Aggregator) expressionAnalyzer.analyze(uExpr, context));
+    for (UnresolvedExpression expr : node.getAggExprList()) {
+      aggregatorBuilder.add((Aggregator) expressionAnalyzer.analyze(expr, context));
     }
 
     ImmutableList.Builder<Expression> groupbyBuilder = new ImmutableList.Builder<>();
-    for (UnresolvedExpression uExpr : node.getGroupExprList()) {
-      groupbyBuilder.add(expressionAnalyzer.analyze(uExpr, context));
+    for (UnresolvedExpression expr : node.getGroupExprList()) {
+      groupbyBuilder.add(expressionAnalyzer.analyze(expr, context));
     }
     return new LogicalAggregation(child, aggregatorBuilder.build(), groupbyBuilder.build());
   }
@@ -155,7 +159,9 @@ public LogicalPlan visitProject(Project node, AnalysisContext context) {
     return new LogicalProject(child, referenceExpressions);
   }
 
-  /** Build {@link LogicalEval} */
+  /**
+   * Build {@link LogicalEval}.
+   */
   @Override
   public LogicalPlan visitEval(Eval node, AnalysisContext context) {
     LogicalPlan child = node.getChild().get(0).accept(this, context);
@@ -172,7 +178,9 @@ public LogicalPlan visitEval(Eval node, AnalysisContext context) {
     return new LogicalEval(child, expressionsBuilder.build());
   }
 
-  /** Build {@link LogicalSort} */
+  /**
+   * Build {@link LogicalSort}.
+   */
   @Override
   public LogicalPlan visitSort(Sort node, AnalysisContext context) {
     LogicalPlan child = node.getChild().get(0).accept(this, context);
@@ -193,7 +201,9 @@ public LogicalPlan visitSort(Sort node, AnalysisContext context) {
     return new LogicalSort(child, count, sortList);
   }
 
-  /** Build {@link LogicalDedupe} */
+  /**
+   * Build {@link LogicalDedupe}.
+   */
   @Override
   public LogicalPlan visitDedupe(Dedupe node, AnalysisContext context) {
     LogicalPlan child = node.getChild().get(0).accept(this, context);
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzer.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzer.java
index bc0146fc22..6f724a9a54 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzer.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzer.java
@@ -43,7 +43,7 @@
 
 /**
  * Analyze the {@link UnresolvedExpression} in the {@link AnalysisContext} to construct the {@link
- * Expression}
+ * Expression}.
  */
 public class ExpressionAnalyzer extends AbstractNodeVisitor<Expression, AnalysisContext> {
   private final BuiltinFunctionRepository repository;
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironment.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironment.java
index cb05efb1a0..dac91e4a25 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironment.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironment.java
@@ -23,63 +23,62 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.expression.ReferenceExpression;
 import com.amazon.opendistroforelasticsearch.sql.expression.env.Environment;
-import lombok.Getter;
-
 import java.util.Optional;
+import lombok.Getter;
 
 /**
  * The definition of Type Environment.
  */
 public class TypeEnvironment implements Environment<Expression, ExprType> {
-    @Getter
-    private final TypeEnvironment parent;
-    private final SymbolTable symbolTable;
+  @Getter
+  private final TypeEnvironment parent;
+  private final SymbolTable symbolTable;
 
-    public TypeEnvironment(TypeEnvironment parent) {
-        this.parent = parent;
-        this.symbolTable = new SymbolTable();
-    }
+  public TypeEnvironment(TypeEnvironment parent) {
+    this.parent = parent;
+    this.symbolTable = new SymbolTable();
+  }
 
-    public TypeEnvironment(TypeEnvironment parent, SymbolTable symbolTable) {
-        this.parent = parent;
-        this.symbolTable = symbolTable;
-    }
+  public TypeEnvironment(TypeEnvironment parent, SymbolTable symbolTable) {
+    this.parent = parent;
+    this.symbolTable = symbolTable;
+  }
 
-    /**
-     * Resolve the {@link Expression} from environment.
-     *
-     * @param var expression
-     * @return resolved {@link ExprType}
-     */
-    @Override
-    public ExprType resolve(Expression var) {
-        if (var instanceof ReferenceExpression) {
-            ReferenceExpression ref = (ReferenceExpression) var;
-            for (TypeEnvironment cur = this; cur != null; cur = cur.parent) {
-                Optional<ExprType> typeOptional = cur.symbolTable.lookup(new Symbol(Namespace.FIELD_NAME,
-                        ref.getAttr()));
-                if (typeOptional.isPresent()) {
-                    return typeOptional.get();
-                }
-            }
+  /**
+   * Resolve the {@link Expression} from environment.
+   *
+   * @param var expression
+   * @return resolved {@link ExprType}
+   */
+  @Override
+  public ExprType resolve(Expression var) {
+    if (var instanceof ReferenceExpression) {
+      ReferenceExpression ref = (ReferenceExpression) var;
+      for (TypeEnvironment cur = this; cur != null; cur = cur.parent) {
+        Optional<ExprType> typeOptional = cur.symbolTable.lookup(new Symbol(Namespace.FIELD_NAME,
+            ref.getAttr()));
+        if (typeOptional.isPresent()) {
+          return typeOptional.get();
         }
-        throw new SemanticCheckException(String.format("can't resolve expression %s in type env", var));
+      }
     }
+    throw new SemanticCheckException(String.format("can't resolve expression %s in type env", var));
+  }
 
-    /**
-     * Define symbol with the type
-     *
-     * @param var  symbol to define
-     * @param type type
-     */
-    public void define(Expression var, ExprType type) {
-        if (var instanceof ReferenceExpression) {
-            ReferenceExpression ref = (ReferenceExpression) var;
-            symbolTable.store(new Symbol(Namespace.FIELD_NAME, ref.getAttr()), type);
-        } else {
-            throw new IllegalArgumentException(String.format("only support define reference, unexpected expression %s"
-                    , var));
-        }
+  /**
+   * Define symbol with the type.
+   *
+   * @param var  symbol to define
+   * @param type type
+   */
+  public void define(Expression var, ExprType type) {
+    if (var instanceof ReferenceExpression) {
+      ReferenceExpression ref = (ReferenceExpression) var;
+      symbolTable.store(new Symbol(Namespace.FIELD_NAME, ref.getAttr()), type);
+    } else {
+      throw new IllegalArgumentException(
+          String.format("only support define reference, unexpected expression %s", var));
     }
+  }
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Namespace.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Namespace.java
index 79fd719f31..f7a17c5706 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Namespace.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Namespace.java
@@ -16,17 +16,17 @@
 package com.amazon.opendistroforelasticsearch.sql.analysis.symbol;
 
 /**
- * Namespace of symbol to avoid naming conflict
+ * Namespace of symbol to avoid naming conflict.
  */
 public enum Namespace {
 
-    FIELD_NAME("Field"),
-    FUNCTION_NAME("Function");
+  FIELD_NAME("Field"),
+  FUNCTION_NAME("Function");
 
-    private final String name;
+  private final String name;
 
-    Namespace(String name) {
-        this.name = name;
-    }
+  Namespace(String name) {
+    this.name = name;
+  }
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Symbol.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Symbol.java
index e5a734b505..d36c1de481 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Symbol.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/Symbol.java
@@ -19,11 +19,11 @@
 import lombok.RequiredArgsConstructor;
 
 /**
- * Symbol in the scope
+ * Symbol in the scope.
  */
 @Getter
 @RequiredArgsConstructor
 public class Symbol {
-    private final Namespace namespace;
-    private final String name;
+  private final Namespace namespace;
+  private final String name;
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTable.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTable.java
index ea3daa18af..a646413383 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTable.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTable.java
@@ -15,70 +15,76 @@
 
 package com.amazon.opendistroforelasticsearch.sql.analysis.symbol;
 
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import static java.util.Collections.emptyMap;
+import static java.util.Collections.emptyNavigableMap;
 
+import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import java.util.EnumMap;
 import java.util.Map;
 import java.util.NavigableMap;
 import java.util.Optional;
 import java.util.TreeMap;
 
-import static java.util.Collections.emptyMap;
-import static java.util.Collections.emptyNavigableMap;
-
 /**
  * Symbol table for symbol definition and resolution.
  */
 public class SymbolTable {
 
-    /** Two-dimension hash table to manage symbols with type in different namespace */
-    private Map<Namespace, NavigableMap<String, ExprType>> tableByNamespace = new EnumMap<>(Namespace.class);
+  /**
+   * Two-dimension hash table to manage symbols with type in different namespace.
+   */
+  private Map<Namespace, NavigableMap<String, ExprType>> tableByNamespace =
+      new EnumMap<>(Namespace.class);
 
-    /**
-     * Store symbol with the type. Create new map for namespace for the first time.
-     * @param symbol    symbol to define
-     * @param type      symbol type
-     */
-    public void store(Symbol symbol, ExprType type) {
-        tableByNamespace.computeIfAbsent(
-                symbol.getNamespace(),
-                ns -> new TreeMap<>()
-        ).put(symbol.getName(), type);
-    }
+  /**
+   * Store symbol with the type. Create new map for namespace for the first time.
+   *
+   * @param symbol symbol to define
+   * @param type   symbol type
+   */
+  public void store(Symbol symbol, ExprType type) {
+    tableByNamespace.computeIfAbsent(
+        symbol.getNamespace(),
+        ns -> new TreeMap<>()
+    ).put(symbol.getName(), type);
+  }
 
-    /**
-     * Look up symbol in the namespace map.
-     * @param symbol    symbol to look up
-     * @return          symbol type which is optional
-     */
-    public Optional<ExprType> lookup(Symbol symbol) {
-        Map<String, ExprType> table = tableByNamespace.get(symbol.getNamespace());
-        ExprType type = null;
-        if (table != null) {
-            type = table.get(symbol.getName());
-        }
-        return Optional.ofNullable(type);
+  /**
+   * Look up symbol in the namespace map.
+   *
+   * @param symbol symbol to look up
+   * @return symbol type which is optional
+   */
+  public Optional<ExprType> lookup(Symbol symbol) {
+    Map<String, ExprType> table = tableByNamespace.get(symbol.getNamespace());
+    ExprType type = null;
+    if (table != null) {
+      type = table.get(symbol.getName());
     }
+    return Optional.ofNullable(type);
+  }
 
-    /**
-     * Look up symbols by a prefix.
-     * @param prefix    a symbol prefix
-     * @return          symbols starting with the prefix
-     */
-    public Map<String, ExprType> lookupByPrefix(Symbol prefix) {
-        NavigableMap<String, ExprType> table = tableByNamespace.get(prefix.getNamespace());
-        if (table != null) {
-            return table.subMap(prefix.getName(), prefix.getName() + Character.MAX_VALUE);
-        }
-        return emptyMap();
+  /**
+   * Look up symbols by a prefix.
+   *
+   * @param prefix a symbol prefix
+   * @return symbols starting with the prefix
+   */
+  public Map<String, ExprType> lookupByPrefix(Symbol prefix) {
+    NavigableMap<String, ExprType> table = tableByNamespace.get(prefix.getNamespace());
+    if (table != null) {
+      return table.subMap(prefix.getName(), prefix.getName() + Character.MAX_VALUE);
     }
+    return emptyMap();
+  }
 
-    /**
-     * Check if namespace map in empty (none definition)
-     * @param namespace     a namespace
-     * @return              true for empty
-     */
-    public boolean isEmpty(Namespace namespace) {
-        return tableByNamespace.getOrDefault(namespace, emptyNavigableMap()).isEmpty();
-    }
+  /**
+   * Check if namespace map in empty (none definition).
+   *
+   * @param namespace a namespace
+   * @return true for empty
+   */
+  public boolean isEmpty(Namespace namespace) {
+    return tableByNamespace.getOrDefault(namespace, emptyNavigableMap()).isEmpty();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/AbstractNodeVisitor.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/AbstractNodeVisitor.java
index fd32458892..7e3b161ec8 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/AbstractNodeVisitor.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/AbstractNodeVisitor.java
@@ -40,13 +40,21 @@
 import com.amazon.opendistroforelasticsearch.sql.ast.tree.Rename;
 import com.amazon.opendistroforelasticsearch.sql.ast.tree.Sort;
 
-/** AST nodes visitor Defines the traverse path */
+/**
+ * AST nodes visitor Defines the traverse path.
+ */
 public abstract class AbstractNodeVisitor<T, C> {
 
   public T visit(Node node, C context) {
     return null;
   }
 
+  /**
+   * Visit child node.
+   * @param node {@link Node}
+   * @param context Context
+   * @return Return Type.
+   */
   public T visitChildren(Node node, C context) {
     T result = defaultResult();
 
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/Node.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/Node.java
index c9774342f6..e4701e09fa 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/Node.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/Node.java
@@ -20,17 +20,17 @@
 import lombok.ToString;
 
 /**
- * AST node
+ * AST node.
  */
 @EqualsAndHashCode
 @ToString
 public abstract class Node {
 
-    public <R, C> R accept(AbstractNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitChildren(this, context);
-    }
+  public <R, C> R accept(AbstractNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitChildren(this, context);
+  }
 
-    public List<? extends Node> getChild() {
-        return null;
-    }
+  public List<? extends Node> getChild() {
+    return null;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/dsl/AstDSL.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/dsl/AstDSL.java
index 76c6990460..1e1cb911a2 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/dsl/AstDSL.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/dsl/AstDSL.java
@@ -43,8 +43,12 @@
 import com.amazon.opendistroforelasticsearch.sql.ast.tree.UnresolvedPlan;
 import java.util.Arrays;
 import java.util.List;
+import lombok.experimental.UtilityClass;
 
-/** Class of static methods to create specific node instances */
+/**
+ * Class of static methods to create specific node instances.
+ */
+@UtilityClass
 public class AstDSL {
 
   public static UnresolvedPlan filter(UnresolvedPlan input, UnresolvedExpression expression) {
@@ -205,6 +209,9 @@ public static List<Argument> defaultFieldsArgs() {
     return exprList(argument("exclude", booleanLiteral(false)));
   }
 
+  /**
+   * Default Stats Command Args.
+   */
   public static List<Argument> defaultStatsArgs() {
     return exprList(
         argument("partitions", intLiteral(1)),
@@ -213,6 +220,9 @@ public static List<Argument> defaultStatsArgs() {
         argument("dedupsplit", booleanLiteral(false)));
   }
 
+  /**
+   * Default Dedup Command Args.
+   */
   public static List<Argument> defaultDedupArgs() {
     return exprList(
         argument("number", intLiteral(1)),
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AggregateFunction.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AggregateFunction.java
index 38b0466580..dac1445426 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AggregateFunction.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AggregateFunction.java
@@ -23,35 +23,40 @@
 import lombok.RequiredArgsConstructor;
 
 /**
- * Expression node of aggregate functions
- * Params include aggregate function name (AVG, SUM, MAX etc.) and the field to aggregate
+ * Expression node of aggregate functions.
+ * Params include aggregate function name (AVG, SUM, MAX etc.) and the field to aggregate.
  */
 @Getter
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class AggregateFunction extends UnresolvedExpression {
-    private final String funcName;
-    private final UnresolvedExpression field;
-    private final List<UnresolvedExpression> argList;
+  private final String funcName;
+  private final UnresolvedExpression field;
+  private final List<UnresolvedExpression> argList;
 
-    public AggregateFunction(String funcName, UnresolvedExpression field) {
-        this.funcName = funcName;
-        this.field = field;
-        this.argList = Collections.emptyList();
-    }
+  /**
+   * Constructor.
+   * @param funcName function name.
+   * @param field {@link UnresolvedExpression}.
+   */
+  public AggregateFunction(String funcName, UnresolvedExpression field) {
+    this.funcName = funcName;
+    this.field = field;
+    this.argList = Collections.emptyList();
+  }
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Collections.singletonList(field);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Collections.singletonList(field);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitAggregateFunction(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitAggregateFunction(this, context);
+  }
 
-    @Override
-    public String toString() {
-        return String.format("%s(%s)", funcName, field);
-    }
+  @Override
+  public String toString() {
+    return String.format("%s(%s)", funcName, field);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/And.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/And.java
index fbda17d1b4..6bab1bd33e 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/And.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/And.java
@@ -24,23 +24,23 @@
 import lombok.ToString;
 
 /**
- * Expression node of logic AND
+ * Expression node of logic AND.
  */
 @Getter
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class And extends UnresolvedExpression {
-    private final UnresolvedExpression left;
-    private final UnresolvedExpression right;
+  private final UnresolvedExpression left;
+  private final UnresolvedExpression right;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(left, right);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(left, right);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitAnd(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitAnd(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Argument.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Argument.java
index 31da0acb44..7f16b16ece 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Argument.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Argument.java
@@ -23,21 +23,25 @@
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
+/**
+ * Argument.
+ */
 @Getter
 @ToString
 @RequiredArgsConstructor
 @EqualsAndHashCode(callSuper = false)
 public class Argument extends UnresolvedExpression {
-    private final String argName;
-    private final Literal value;
-    //    private final DataType valueType;
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(value);
-    }
+  private final String argName;
+  private final Literal value;
+
+  //    private final DataType valueType;
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(value);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitArgument(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitArgument(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AttributeList.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AttributeList.java
index 069d44d0a7..b659365834 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AttributeList.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/AttributeList.java
@@ -24,22 +24,22 @@
 import lombok.ToString;
 
 /**
- * Expression node that includes a list of Expression nodes
+ * Expression node that includes a list of Expression nodes.
  */
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @AllArgsConstructor
 public class AttributeList extends UnresolvedExpression {
-    @Getter
-    private List<UnresolvedExpression> attrList;
+  @Getter
+  private List<UnresolvedExpression> attrList;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return ImmutableList.copyOf(attrList);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return ImmutableList.copyOf(attrList);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitAttributeList(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitAttributeList(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Compare.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Compare.java
index 5a3a4e42a3..5ba9383dc7 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Compare.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Compare.java
@@ -28,16 +28,17 @@
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Compare extends UnresolvedExpression {
-    private final String operator;
-    private final UnresolvedExpression left;
-    private final UnresolvedExpression right;
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(left, right);
-    }
+  private final String operator;
+  private final UnresolvedExpression left;
+  private final UnresolvedExpression right;
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitCompare(this, context);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(left, right);
+  }
+
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitCompare(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/DataType.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/DataType.java
index 683d1eb70a..51662e6c53 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/DataType.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/DataType.java
@@ -16,11 +16,11 @@
 package com.amazon.opendistroforelasticsearch.sql.ast.expression;
 
 public enum DataType {
-    TYPE_ERROR,
-    NULL,
+  TYPE_ERROR,
+  NULL,
 
-    INTEGER,
-    DOUBLE,
-    STRING,
-    BOOLEAN
+  INTEGER,
+  DOUBLE,
+  STRING,
+  BOOLEAN
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/EqualTo.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/EqualTo.java
index faa95af8d3..5d745314f0 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/EqualTo.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/EqualTo.java
@@ -24,24 +24,24 @@
 import lombok.ToString;
 
 /**
- * Expression node of binary operator or comparison relation EQUAL
+ * Expression node of binary operator or comparison relation EQUAL.
  */
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @AllArgsConstructor
 public class EqualTo extends UnresolvedExpression {
-    @Getter
-    private UnresolvedExpression left;
-    @Getter
-    private UnresolvedExpression right;
+  @Getter
+  private UnresolvedExpression left;
+  @Getter
+  private UnresolvedExpression right;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(left, right);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(left, right);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitEqualTo(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitEqualTo(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Field.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Field.java
index 1825760459..c8152f280d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Field.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Field.java
@@ -29,33 +29,33 @@
 @EqualsAndHashCode(callSuper = false)
 @AllArgsConstructor
 public class Field extends UnresolvedExpression {
-    private QualifiedName field;
-    private List<Argument> fieldArgs = Collections.emptyList();
-
-    public Field(QualifiedName field) {
-        this.field = field;
-    }
-
-    public Field(String field) {
-        this.field = new QualifiedName(field);
-    }
-
-    public Field(String field, List<Argument> fieldArgs) {
-        this.field = new QualifiedName(field);
-        this.fieldArgs = fieldArgs;
-    }
-
-    public boolean hasArgument() {
-        return !fieldArgs.isEmpty();
-    }
-
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return ImmutableList.of(this.field);
-    }
-
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitField(this, context);
-    }
+  private QualifiedName field;
+  private List<Argument> fieldArgs = Collections.emptyList();
+
+  public Field(QualifiedName field) {
+    this.field = field;
+  }
+
+  public Field(String field) {
+    this.field = new QualifiedName(field);
+  }
+
+  public Field(String field, List<Argument> fieldArgs) {
+    this.field = new QualifiedName(field);
+    this.fieldArgs = fieldArgs;
+  }
+
+  public boolean hasArgument() {
+    return !fieldArgs.isEmpty();
+  }
+
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return ImmutableList.of(this.field);
+  }
+
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitField(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Function.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Function.java
index 42b01cc645..e4b12ea3a3 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Function.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Function.java
@@ -24,7 +24,7 @@
 import lombok.ToString;
 
 /**
- * Expression node of scalar function
+ * Expression node of scalar function.
  * Params include function name (@funcName) and function arguments (@funcArgs)
  */
 @Getter
@@ -32,16 +32,16 @@
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Function extends UnresolvedExpression {
-    private final String funcName;
-    private final List<UnresolvedExpression> funcArgs;
+  private final String funcName;
+  private final List<UnresolvedExpression> funcArgs;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return ImmutableList.of();
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return ImmutableList.of();
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitFunction(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitFunction(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/In.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/In.java
index 07343082fe..365787780b 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/In.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/In.java
@@ -24,25 +24,26 @@
 import lombok.ToString;
 
 /**
- * Expression node of one-to-many mapping relation IN
- * Params include the field expression and/or wildcard field expression, nested field expression (@field)
- * And the values that the field is mapped to (@valueList)
+ * Expression node of one-to-many mapping relation IN.
+ * Params include the field expression and/or wildcard field expression,
+ * nested field expression (@field).
+ * And the values that the field is mapped to (@valueList).
  */
 @Getter
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class In extends UnresolvedExpression {
-    private final UnresolvedExpression field;
-    private final List<UnresolvedExpression> valueList;
+  private final UnresolvedExpression field;
+  private final List<UnresolvedExpression> valueList;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(field);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(field);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitIn(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitIn(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Let.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Let.java
index 68d3862ee1..c4109e8b13 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Let.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Let.java
@@ -23,7 +23,9 @@
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-/** Represent the assign operation. e.g. velocity = distance/speed. */
+/**
+ * Represent the assign operation. e.g. velocity = distance/speed.
+ */
 @Getter
 @ToString
 @EqualsAndHashCode(callSuper = false)
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Literal.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Literal.java
index 884f0642f0..5a0f60175c 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Literal.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Literal.java
@@ -25,7 +25,8 @@
 
 /**
  * Expression node of literal type
- * Params include literal value (@value) and literal data type (@type) which can be selected from {@link DataType}
+ * Params include literal value (@value) and
+ * literal data type (@type) which can be selected from {@link DataType}.
  */
 @Getter
 @ToString
@@ -33,16 +34,16 @@
 @RequiredArgsConstructor
 public class Literal extends UnresolvedExpression {
 
-    private final Object value;
-    private final DataType type;
+  private final Object value;
+  private final DataType type;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return ImmutableList.of();
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return ImmutableList.of();
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitLiteral(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitLiteral(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Map.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Map.java
index bca06f6f54..6fe1f307c5 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Map.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Map.java
@@ -24,23 +24,23 @@
 import lombok.ToString;
 
 /**
- * Expression node of one-to-one mapping relation
+ * Expression node of one-to-one mapping relation.
  */
 @Getter
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Map extends UnresolvedExpression {
-    private final UnresolvedExpression origin;
-    private final UnresolvedExpression target;
+  private final UnresolvedExpression origin;
+  private final UnresolvedExpression target;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(origin, target);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(origin, target);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitMap(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitMap(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Not.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Not.java
index c294e86e71..1597b4fe55 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Not.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Not.java
@@ -24,22 +24,22 @@
 import lombok.ToString;
 
 /**
- * Expression node of the logic NOT
+ * Expression node of the logic NOT.
  */
 @Getter
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Not extends UnresolvedExpression {
-    private final UnresolvedExpression expression;
+  private final UnresolvedExpression expression;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(expression);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(expression);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitNot(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitNot(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Or.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Or.java
index cfe6c3df91..8ed108f591 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Or.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/Or.java
@@ -24,23 +24,23 @@
 import lombok.ToString;
 
 /**
- * Expression node of the logic OR
+ * Expression node of the logic OR.
  */
 @Getter
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Or extends UnresolvedExpression {
-    private final UnresolvedExpression left;
-    private final UnresolvedExpression right;
+  private final UnresolvedExpression left;
+  private final UnresolvedExpression right;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return Arrays.asList(left, right);
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return Arrays.asList(left, right);
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitOr(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitOr(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/QualifiedName.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/QualifiedName.java
index cf4d656f84..3d1e35ff06 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/QualifiedName.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/QualifiedName.java
@@ -15,6 +15,9 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ast.expression;
 
+import static java.util.Objects.requireNonNull;
+import static java.util.stream.Collectors.toList;
+
 import com.amazon.opendistroforelasticsearch.sql.ast.AbstractNodeVisitor;
 import com.google.common.collect.ImmutableList;
 import java.util.ArrayList;
@@ -26,60 +29,66 @@
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 
-import static java.util.Objects.requireNonNull;
-import static java.util.stream.Collectors.toList;
-
 @Getter
 @EqualsAndHashCode(callSuper = false)
 public class QualifiedName extends UnresolvedExpression {
-    private final List<String> parts;
+  private final List<String> parts;
 
-    public QualifiedName(String name) {
-        this.parts = Collections.singletonList(name);
-    }
+  public QualifiedName(String name) {
+    this.parts = Collections.singletonList(name);
+  }
 
-    public QualifiedName(Iterable<String> parts) {
-        List<String> partsList = StreamSupport.stream(parts.spliterator(), false).collect(toList());
-        if (partsList.isEmpty()) {
-            throw new IllegalArgumentException("parts is empty");
-        }
-        this.parts = partsList;
+  /**
+   * QualifiedName Constructor.
+   */
+  public QualifiedName(Iterable<String> parts) {
+    List<String> partsList = StreamSupport.stream(parts.spliterator(), false).collect(toList());
+    if (partsList.isEmpty()) {
+      throw new IllegalArgumentException("parts is empty");
     }
+    this.parts = partsList;
+  }
 
-    public static QualifiedName of(String first, String... rest) {
-        requireNonNull(first);
-        ArrayList<String> parts = new ArrayList<>();
-        parts.add(first);
-        parts.addAll(Arrays.asList(rest));
-        return new QualifiedName(parts);
-    }
+  /**
+   * Construct {@link QualifiedName} from list of string.
+   */
+  public static QualifiedName of(String first, String... rest) {
+    requireNonNull(first);
+    ArrayList<String> parts = new ArrayList<>();
+    parts.add(first);
+    parts.addAll(Arrays.asList(rest));
+    return new QualifiedName(parts);
+  }
 
-    private static QualifiedName of(Iterable<String> parts) {
-        return new QualifiedName(parts);
-    }
+  private static QualifiedName of(Iterable<String> parts) {
+    return new QualifiedName(parts);
+  }
 
-    public Optional<QualifiedName> getPrefix() {
-        if (parts.size() == 1) {
-            return Optional.empty();
-        }
-        return Optional.of(QualifiedName.of(parts.subList(0, parts.size() - 1)));
+  /**
+   * Get Prefix of {@link QualifiedName}.
+   */
+  public Optional<QualifiedName> getPrefix() {
+    if (parts.size() == 1) {
+      return Optional.empty();
     }
+    return Optional.of(QualifiedName.of(parts.subList(0, parts.size() - 1)));
+  }
 
-    public String getSuffix() {
-        return parts.get(parts.size() - 1);
-    }
+  public String getSuffix() {
+    return parts.get(parts.size() - 1);
+  }
 
-    public String toString() {
-        return String.join(".", this.parts);
-    }
+  public String toString() {
+    return String.join(".", this.parts);
+  }
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return ImmutableList.of();
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return ImmutableList.of();
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitQualifiedName(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitQualifiedName(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedAttribute.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedAttribute.java
index 9c2450f5ca..a08e762e15 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedAttribute.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedAttribute.java
@@ -24,7 +24,8 @@
 import lombok.ToString;
 
 /**
- * Expression node, representing the syntax that is not resolved to any other expression nodes yet but non-negligible
+ * Expression node, representing the syntax that is not resolved to
+ * any other expression nodes yet but non-negligible
  * This expression is often created as the index name, field name etc.
  */
 @ToString
@@ -32,15 +33,15 @@
 @RequiredArgsConstructor
 @Getter
 public class UnresolvedAttribute extends UnresolvedExpression {
-    private final String attr;
+  private final String attr;
 
-    @Override
-    public List<UnresolvedExpression> getChild() {
-        return ImmutableList.of();
-    }
+  @Override
+  public List<UnresolvedExpression> getChild() {
+    return ImmutableList.of();
+  }
 
-    @Override
-    public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
-        return nodeVisitor.visitUnresolvedAttribute(this, context);
-    }
+  @Override
+  public <R, C> R accept(AbstractNodeVisitor<R, C> nodeVisitor, C context) {
+    return nodeVisitor.visitUnresolvedAttribute(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedExpression.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedExpression.java
index 1507b68832..e63aa167df 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedExpression.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/expression/UnresolvedExpression.java
@@ -23,8 +23,8 @@
 @EqualsAndHashCode(callSuper = false)
 @ToString
 public abstract class UnresolvedExpression extends Node {
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-        return nodeVisitor.visitChildren(this, context);
-    }
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitChildren(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Aggregation.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Aggregation.java
index bc7eb46eff..c996c205bb 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Aggregation.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Aggregation.java
@@ -27,55 +27,58 @@
 import lombok.ToString;
 
 /**
- * Logical plan node of Aggregation, the interface for building aggregation actions in queries
+ * Logical plan node of Aggregation, the interface for building aggregation actions in queries.
  */
 @Getter
 @Setter
 @ToString
 @EqualsAndHashCode(callSuper = false)
 public class Aggregation extends UnresolvedPlan {
-    private List<UnresolvedExpression> aggExprList;
-    private List<UnresolvedExpression> sortExprList;
-    private List<UnresolvedExpression> groupExprList;
-    private List<Argument> argExprList;
-    private UnresolvedPlan child;
+  private List<UnresolvedExpression> aggExprList;
+  private List<UnresolvedExpression> sortExprList;
+  private List<UnresolvedExpression> groupExprList;
+  private List<Argument> argExprList;
+  private UnresolvedPlan child;
 
-    public Aggregation(List<UnresolvedExpression> aggExprList,
-                       List<UnresolvedExpression> sortExprList,
-                       List<UnresolvedExpression> groupExprList) {
-        this.aggExprList = aggExprList;
-        this.sortExprList = sortExprList;
-        this.groupExprList = groupExprList;
-        this.argExprList = Collections.emptyList();
-    }
+  /**
+   * Aggregation Constructor without argument.
+   */
+  public Aggregation(List<UnresolvedExpression> aggExprList,
+                     List<UnresolvedExpression> sortExprList,
+                     List<UnresolvedExpression> groupExprList) {
+    this(aggExprList, sortExprList, groupExprList, Collections.emptyList());
+  }
 
-    public Aggregation(List<UnresolvedExpression> aggExprList,
-                       List<UnresolvedExpression> sortExprList,
-                       List<UnresolvedExpression> groupExprList,
-                       List<Argument> argExprList) {
-        this.aggExprList = aggExprList;
-        this.sortExprList = sortExprList;
-        this.groupExprList = groupExprList;
-        this.argExprList = argExprList;
-    }
+  /**
+   * Aggregation Constructor.
+   */
+  public Aggregation(List<UnresolvedExpression> aggExprList,
+                     List<UnresolvedExpression> sortExprList,
+                     List<UnresolvedExpression> groupExprList,
+                     List<Argument> argExprList) {
+    this.aggExprList = aggExprList;
+    this.sortExprList = sortExprList;
+    this.groupExprList = groupExprList;
+    this.argExprList = argExprList;
+  }
 
-    public boolean hasArgument() {
-        return !aggExprList.isEmpty();
-    }
+  public boolean hasArgument() {
+    return !aggExprList.isEmpty();
+  }
 
-    @Override
-    public Aggregation attach(UnresolvedPlan child) {
-        this.child = child;
-        return this;
-    }
+  @Override
+  public Aggregation attach(UnresolvedPlan child) {
+    this.child = child;
+    return this;
+  }
 
-    @Override
-    public List<UnresolvedPlan> getChild() {
-        return ImmutableList.of(this.child);
-    }
+  @Override
+  public List<UnresolvedPlan> getChild() {
+    return ImmutableList.of(this.child);
+  }
 
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-        return nodeVisitor.visitAggregation(this, context);
-    }
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitAggregation(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Eval.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Eval.java
index 3f2f3856ea..23ba92d815 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Eval.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Eval.java
@@ -25,7 +25,9 @@
 import lombok.Setter;
 import lombok.ToString;
 
-/** AST node represent Eval operation. */
+/**
+ * AST node represent Eval operation.
+ */
 @Getter
 @Setter
 @ToString
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Filter.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Filter.java
index fc7f651192..7f8626b846 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Filter.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Filter.java
@@ -24,32 +24,32 @@
 import lombok.ToString;
 
 /**
- * Logical plan node of Filter, the interface for building filters in queries
+ * Logical plan node of Filter, the interface for building filters in queries.
  */
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @Getter
 public class Filter extends UnresolvedPlan {
-    private UnresolvedExpression condition;
-    private UnresolvedPlan child;
+  private UnresolvedExpression condition;
+  private UnresolvedPlan child;
 
-    public Filter(UnresolvedExpression condition) {
-        this.condition = condition;
-    }
+  public Filter(UnresolvedExpression condition) {
+    this.condition = condition;
+  }
 
-    @Override
-    public Filter attach(UnresolvedPlan child) {
-        this.child = child;
-        return this;
-    }
+  @Override
+  public Filter attach(UnresolvedPlan child) {
+    this.child = child;
+    return this;
+  }
 
-    @Override
-    public List<UnresolvedPlan> getChild() {
-        return ImmutableList.of(child);
-    }
+  @Override
+  public List<UnresolvedPlan> getChild() {
+    return ImmutableList.of(child);
+  }
 
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-        return nodeVisitor.visitFilter(this, context);
-    }
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitFilter(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Project.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Project.java
index a47b8d2bfd..c11018192f 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Project.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Project.java
@@ -27,45 +27,45 @@
 import lombok.ToString;
 
 /**
- * Logical plan node of Project, the interface for building the list of searching fields
+ * Logical plan node of Project, the interface for building the list of searching fields.
  */
 @ToString
 @Getter
 @EqualsAndHashCode(callSuper = false)
 public class Project extends UnresolvedPlan {
-    @Setter
-    private List<UnresolvedExpression> projectList;
-    private List<Argument> argExprList;
-    private UnresolvedPlan child;
+  @Setter
+  private List<UnresolvedExpression> projectList;
+  private List<Argument> argExprList;
+  private UnresolvedPlan child;
 
-    public Project(List<UnresolvedExpression> projectList) {
-        this.projectList = projectList;
-        this.argExprList = Collections.emptyList();
-    }
+  public Project(List<UnresolvedExpression> projectList) {
+    this.projectList = projectList;
+    this.argExprList = Collections.emptyList();
+  }
 
-    public Project(List<UnresolvedExpression> projectList, List<Argument> argExprList) {
-        this.projectList = projectList;
-        this.argExprList = argExprList;
-    }
+  public Project(List<UnresolvedExpression> projectList, List<Argument> argExprList) {
+    this.projectList = projectList;
+    this.argExprList = argExprList;
+  }
 
-    public boolean hasArgument() {
-        return !argExprList.isEmpty();
-    }
+  public boolean hasArgument() {
+    return !argExprList.isEmpty();
+  }
 
-    @Override
-    public Project attach(UnresolvedPlan child) {
-        this.child = child;
-        return this;
-    }
+  @Override
+  public Project attach(UnresolvedPlan child) {
+    this.child = child;
+    return this;
+  }
 
-    @Override
-    public List<UnresolvedPlan> getChild() {
-        return ImmutableList.of(this.child);
-    }
+  @Override
+  public List<UnresolvedPlan> getChild() {
+    return ImmutableList.of(this.child);
+  }
 
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
 
-        return nodeVisitor.visitProject(this, context);
-    }
+    return nodeVisitor.visitProject(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Relation.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Relation.java
index f827c88018..9fa002e177 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Relation.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Relation.java
@@ -24,30 +24,30 @@
 import lombok.ToString;
 
 /**
- * Logical plan node of Relation, the interface for building the searching sources
+ * Logical plan node of Relation, the interface for building the searching sources.
  */
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @RequiredArgsConstructor
 public class Relation extends UnresolvedPlan {
-    private final UnresolvedExpression tableName;
+  private final UnresolvedExpression tableName;
 
-    public String getTableName() {
-        return tableName.toString();
-    }
+  public String getTableName() {
+    return tableName.toString();
+  }
 
-    @Override
-    public List<UnresolvedPlan> getChild() {
-        return ImmutableList.of();
-    }
+  @Override
+  public List<UnresolvedPlan> getChild() {
+    return ImmutableList.of();
+  }
 
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-        return nodeVisitor.visitRelation(this, context);
-    }
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitRelation(this, context);
+  }
 
-    @Override
-    public UnresolvedPlan attach(UnresolvedPlan child) {
-        return this;
-    }
+  @Override
+  public UnresolvedPlan attach(UnresolvedPlan child) {
+    return this;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Rename.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Rename.java
index 9b7d0d5cf6..3576a93c36 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Rename.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Rename.java
@@ -18,43 +18,42 @@
 import com.amazon.opendistroforelasticsearch.sql.ast.AbstractNodeVisitor;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Map;
 import com.google.common.collect.ImmutableList;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-import java.util.List;
-
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @Getter
 @RequiredArgsConstructor
 public class Rename extends UnresolvedPlan {
-    private final List<Map> renameList;
-    private UnresolvedPlan child;
-
-    public Rename(List<Map> renameList, UnresolvedPlan child) {
-        this.renameList = renameList;
-        this.child = child;
-    }
-
-    @Override
-    public Rename attach(UnresolvedPlan child) {
-        if (null == this.child) {
-            this.child = child;
-        } else {
-            this.child.attach(child);
-        }
-        return this;
-    }
-
-    @Override
-    public List<UnresolvedPlan> getChild() {
-        return ImmutableList.of(child);
-    }
-
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-        return nodeVisitor.visitRename(this, context);
+  private final List<Map> renameList;
+  private UnresolvedPlan child;
+
+  public Rename(List<Map> renameList, UnresolvedPlan child) {
+    this.renameList = renameList;
+    this.child = child;
+  }
+
+  @Override
+  public Rename attach(UnresolvedPlan child) {
+    if (null == this.child) {
+      this.child = child;
+    } else {
+      this.child.attach(child);
     }
+    return this;
+  }
+
+  @Override
+  public List<UnresolvedPlan> getChild() {
+    return ImmutableList.of(child);
+  }
+
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitRename(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Sort.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Sort.java
index 5eff4ae795..954a338e87 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Sort.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/Sort.java
@@ -32,7 +32,9 @@
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-/** AST node for Sort {@link Sort#sortList} represent a list of sort expression and sort options. */
+/**
+ * AST node for Sort {@link Sort#sortList} represent a list of sort expression and sort options.
+ */
 @ToString
 @EqualsAndHashCode(callSuper = false)
 @Getter
@@ -59,13 +61,19 @@ public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
     return nodeVisitor.visitSort(this, context);
   }
 
-  /** Sort Options. */
+  /**
+   * Sort Options.
+   */
   @Data
   public static class SortOption {
 
-    /** PPL ascending sort option, null first. */
+    /**
+     * PPL ascending sort option, null first.
+     */
     public static SortOption PPL_ASC = new SortOption(ASC, NULL_FIRST);
-    /** PPL descending sort option, null last. */
+    /**
+     * PPL descending sort option, null last.
+     */
     public static SortOption PPL_DESC = new SortOption(DESC, NULL_LAST);
 
     private final SortOrder sortOrder;
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/UnresolvedPlan.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/UnresolvedPlan.java
index ea378b2414..6e2e17c912 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/UnresolvedPlan.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/ast/tree/UnresolvedPlan.java
@@ -21,15 +21,15 @@
 import lombok.ToString;
 
 /**
- * Abstract unresolved plan
+ * Abstract unresolved plan.
  */
 @EqualsAndHashCode(callSuper = false)
 @ToString
 public abstract class UnresolvedPlan extends Node {
-    @Override
-    public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-        return nodeVisitor.visitChildren(this, context);
-    }
+  @Override
+  public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
+    return nodeVisitor.visitChildren(this, context);
+  }
 
-    public abstract UnresolvedPlan attach(UnresolvedPlan child);
+  public abstract UnresolvedPlan attach(UnresolvedPlan child);
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprBooleanValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprBooleanValue.java
index 5753671c9e..0660f2f70e 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprBooleanValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprBooleanValue.java
@@ -19,35 +19,35 @@
 
 @EqualsAndHashCode
 public class ExprBooleanValue implements ExprValue {
-    private static final ExprValue TRUE = new ExprBooleanValue(true);
-    private static final ExprValue FALSE = new ExprBooleanValue(false);
+  private static final ExprValue TRUE = new ExprBooleanValue(true);
+  private static final ExprValue FALSE = new ExprBooleanValue(false);
 
-    private final Boolean value;
+  private final Boolean value;
 
-    private ExprBooleanValue(Boolean value) {
-        this.value = value;
-    }
+  private ExprBooleanValue(Boolean value) {
+    this.value = value;
+  }
 
-    public static ExprValue ofTrue() {
-        return TRUE;
-    }
+  public static ExprValue ofTrue() {
+    return TRUE;
+  }
 
-    public static ExprValue ofFalse() {
-        return FALSE;
-    }
+  public static ExprValue ofFalse() {
+    return FALSE;
+  }
 
-    @Override
-    public Object value() {
-        return value;
-    }
+  @Override
+  public Object value() {
+    return value;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.BOOLEAN;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.BOOLEAN;
+  }
 
-    @Override
-    public String toString() {
-        return value.toString();
-    }
+  @Override
+  public String toString() {
+    return value.toString();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprCollectionValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprCollectionValue.java
index e9eec5f91c..188db3cd41 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprCollectionValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprCollectionValue.java
@@ -15,31 +15,30 @@
 
 package com.amazon.opendistroforelasticsearch.sql.data.model;
 
-import lombok.EqualsAndHashCode;
-import lombok.RequiredArgsConstructor;
-
 import java.util.List;
 import java.util.stream.Collectors;
+import lombok.EqualsAndHashCode;
+import lombok.RequiredArgsConstructor;
 
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ExprCollectionValue implements ExprValue {
-    private final List<ExprValue> valueList;
+  private final List<ExprValue> valueList;
 
-    @Override
-    public Object value() {
-        return valueList;
-    }
+  @Override
+  public Object value() {
+    return valueList;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.ARRAY;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.ARRAY;
+  }
 
-    @Override
-    public String toString() {
-        return valueList.stream()
-                .map(Object::toString)
-                .collect(Collectors.joining(",", "[", "]"));
-    }
+  @Override
+  public String toString() {
+    return valueList.stream()
+        .map(Object::toString)
+        .collect(Collectors.joining(",", "[", "]"));
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprDoubleValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprDoubleValue.java
index b00d64714e..7a6858d0ea 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprDoubleValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprDoubleValue.java
@@ -21,20 +21,20 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ExprDoubleValue implements ExprValue {
-    private final Double value;
+  private final Double value;
 
-    @Override
-    public Object value() {
-        return value;
-    }
+  @Override
+  public Object value() {
+    return value;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.DOUBLE;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.DOUBLE;
+  }
 
-    @Override
-    public String toString() {
-        return value.toString();
-    }
+  @Override
+  public String toString() {
+    return value.toString();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprFloatValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprFloatValue.java
index cdc67a8a64..9dcafc439d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprFloatValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprFloatValue.java
@@ -21,20 +21,20 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ExprFloatValue implements ExprValue {
-    private final Float value;
+  private final Float value;
 
-    @Override
-    public Object value() {
-        return value;
-    }
+  @Override
+  public Object value() {
+    return value;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.FLOAT;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.FLOAT;
+  }
 
-    @Override
-    public String toString() {
-        return value.toString();
-    }
+  @Override
+  public String toString() {
+    return value.toString();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprIntegerValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprIntegerValue.java
index 7536160d6d..8b828bb583 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprIntegerValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprIntegerValue.java
@@ -21,20 +21,20 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ExprIntegerValue implements ExprValue {
-    private final Integer value;
+  private final Integer value;
 
-    @Override
-    public Object value() {
-        return value;
-    }
+  @Override
+  public Object value() {
+    return value;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.INTEGER;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.INTEGER;
+  }
 
-    @Override
-    public String toString() {
-        return value.toString();
-    }
+  @Override
+  public String toString() {
+    return value.toString();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprLongValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprLongValue.java
index 5f81e02142..51f014c7ba 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprLongValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprLongValue.java
@@ -21,20 +21,20 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ExprLongValue implements ExprValue {
-    private final Long value;
+  private final Long value;
 
-    @Override
-    public Object value() {
-        return value;
-    }
+  @Override
+  public Object value() {
+    return value;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.LONG;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.LONG;
+  }
 
-    @Override
-    public String toString() {
-        return value.toString();
-    }
+  @Override
+  public String toString() {
+    return value.toString();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValue.java
index a97e501964..86697b3fb7 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValue.java
@@ -23,27 +23,27 @@
  */
 @EqualsAndHashCode
 public class ExprMissingValue implements ExprValue {
-    private static final ExprValue instance = new ExprMissingValue();
+  private static final ExprValue instance = new ExprMissingValue();
 
-    private ExprMissingValue() {
-    }
+  private ExprMissingValue() {
+  }
 
-    public static ExprValue of() {
-        return instance;
-    }
+  public static ExprValue of() {
+    return instance;
+  }
 
-    @Override
-    public Object value() {
-        throw new ExpressionEvaluationException("invalid to call value operation on missing value");
-    }
+  @Override
+  public Object value() {
+    throw new ExpressionEvaluationException("invalid to call value operation on missing value");
+  }
 
-    @Override
-    public ExprType type() {
-        throw new ExpressionEvaluationException("invalid to call type operation on missing value");
-    }
+  @Override
+  public ExprType type() {
+    throw new ExpressionEvaluationException("invalid to call type operation on missing value");
+  }
 
-    @Override
-    public boolean isMissing() {
-        return true;
-    }
+  @Override
+  public boolean isMissing() {
+    return true;
+  }
 }
\ No newline at end of file
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValue.java
index 7e28a56bb1..d166dd786e 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValue.java
@@ -23,27 +23,27 @@
  */
 @EqualsAndHashCode
 public class ExprNullValue implements ExprValue {
-    private static final ExprValue instance = new ExprNullValue();
+  private static final ExprValue instance = new ExprNullValue();
 
-    private ExprNullValue() {
-    }
+  private ExprNullValue() {
+  }
 
-    public static ExprValue of() {
-        return instance;
-    }
+  public static ExprValue of() {
+    return instance;
+  }
 
-    @Override
-    public Object value() {
-        return null;
-    }
+  @Override
+  public Object value() {
+    return null;
+  }
 
-    @Override
-    public ExprType type() {
-        throw new ExpressionEvaluationException("invalid to call type operation on null value");
-    }
+  @Override
+  public ExprType type() {
+    throw new ExpressionEvaluationException("invalid to call type operation on null value");
+  }
 
-    @Override
-    public boolean isNull() {
-        return true;
-    }
+  @Override
+  public boolean isNull() {
+    return true;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprStringValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprStringValue.java
index eb5400b1a7..d8abd275a5 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprStringValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprStringValue.java
@@ -21,20 +21,20 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ExprStringValue implements ExprValue {
-    private final String value;
+  private final String value;
 
-    @Override
-    public Object value() {
-        return value;
-    }
+  @Override
+  public Object value() {
+    return value;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.STRING;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.STRING;
+  }
 
-    @Override
-    public String toString() {
-        return String.format("\"%s\"", value);
-    }
+  @Override
+  public String toString() {
+    return String.format("\"%s\"", value);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValue.java
index 5be8e7b649..36bf01607f 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValue.java
@@ -27,52 +27,57 @@
 @RequiredArgsConstructor
 public class ExprTupleValue implements ExprValue {
 
-    private final LinkedHashMap<String, ExprValue> valueMap;
+  private final LinkedHashMap<String, ExprValue> valueMap;
 
-    public static ExprTupleValue fromExprValueMap(Map<String, ExprValue> map) {
-        LinkedHashMap<String, ExprValue> linkedHashMap = new LinkedHashMap<>(map);
-        return new ExprTupleValue(linkedHashMap);
-    }
+  public static ExprTupleValue fromExprValueMap(Map<String, ExprValue> map) {
+    LinkedHashMap<String, ExprValue> linkedHashMap = new LinkedHashMap<>(map);
+    return new ExprTupleValue(linkedHashMap);
+  }
 
-    @Override
-    public Object value() {
-        return valueMap;
-    }
+  @Override
+  public Object value() {
+    return valueMap;
+  }
 
-    @Override
-    public ExprType type() {
-        return ExprType.STRUCT;
-    }
+  @Override
+  public ExprType type() {
+    return ExprType.STRUCT;
+  }
 
-    @Override
-    public String toString() {
-        return valueMap.entrySet()
-                .stream()
-                .map(entry -> String.format("%s:%s", entry.getKey(), entry.getValue()))
-                .collect(Collectors.joining(",", "{", "}"));
-    }
+  @Override
+  public String toString() {
+    return valueMap.entrySet()
+        .stream()
+        .map(entry -> String.format("%s:%s", entry.getKey(), entry.getValue()))
+        .collect(Collectors.joining(",", "{", "}"));
+  }
 
-    @Override
-    public BindingTuple bindingTuples() {
-        return new LazyBindingTuple(bindingName -> valueMap.getOrDefault(bindingName, ExprMissingValue.of()));
-    }
+  @Override
+  public BindingTuple bindingTuples() {
+    return new LazyBindingTuple(
+        bindingName -> valueMap.getOrDefault(bindingName, ExprMissingValue.of()));
+  }
 
-    public boolean equals(Object o) {
-        if (o == this) {
-            return true;
-        } else if (!(o instanceof ExprTupleValue)) {
-            return false;
-        } else {
-            ExprTupleValue other = (ExprTupleValue) o;
-            Iterator<Entry<String, ExprValue>> thisIterator = this.valueMap.entrySet().iterator();
-            Iterator<Entry<String, ExprValue>> otherIterator = other.valueMap.entrySet().iterator();
-            while (thisIterator.hasNext() && otherIterator.hasNext()) {
-                if (!thisIterator.next().equals(otherIterator.next())) {
-                    return false;
-                }
-            }
-            return !(thisIterator.hasNext() || otherIterator.hasNext());
+  /**
+   * Override the equals method.
+   * @return true for equal, otherwise false.
+   */
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    } else if (!(o instanceof ExprTupleValue)) {
+      return false;
+    } else {
+      ExprTupleValue other = (ExprTupleValue) o;
+      Iterator<Entry<String, ExprValue>> thisIterator = this.valueMap.entrySet().iterator();
+      Iterator<Entry<String, ExprValue>> otherIterator = other.valueMap.entrySet().iterator();
+      while (thisIterator.hasNext() && otherIterator.hasNext()) {
+        if (!thisIterator.next().equals(otherIterator.next())) {
+          return false;
         }
+      }
+      return !(thisIterator.hasNext() || otherIterator.hasNext());
     }
+  }
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprType.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprType.java
index e6e1dbc755..4b17db27fd 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprType.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprType.java
@@ -19,15 +19,15 @@
  * Expression Type.
  */
 public enum ExprType {
-    UNKNOWN,
+  UNKNOWN,
 
-    DOUBLE,
-    FLOAT,
-    LONG,
-    INTEGER,
+  DOUBLE,
+  FLOAT,
+  LONG,
+  INTEGER,
 
-    BOOLEAN,
-    STRING,
-    STRUCT,
-    ARRAY
+  BOOLEAN,
+  STRING,
+  STRUCT,
+  ARRAY
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValue.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValue.java
index dfb8e01a49..f6f51162fe 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValue.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValue.java
@@ -21,36 +21,38 @@
  * The definition of the Expression Value.
  */
 public interface ExprValue {
-    /**
-     * Get the Object value of the Expression Value.
-     */
-    Object value();
+  /**
+   * Get the Object value of the Expression Value.
+   */
+  Object value();
 
-    /**
-     * Get the {@link ExprType} of the Expression Value.
-     */
-    ExprType type();
+  /**
+   * Get the {@link ExprType} of the Expression Value.
+   */
+  ExprType type();
 
-    /**
-     * Is null value?
-     * @return true: is null value, otherwise false
-     */
-    default boolean isNull() {
-        return false;
-    }
+  /**
+   * Is null value.
+   *
+   * @return true: is null value, otherwise false
+   */
+  default boolean isNull() {
+    return false;
+  }
 
-    /**
-     * Is missing value?
-     * @return true: is missing value, otherwise false
-     */
-    default boolean isMissing() {
-        return false;
-    }
+  /**
+   * Is missing value.
+   *
+   * @return true: is missing value, otherwise false
+   */
+  default boolean isMissing() {
+    return false;
+  }
 
-    /**
-     * Get the {@link BindingTuple}
-     */
-    default BindingTuple bindingTuples() {
-        return BindingTuple.EMPTY;
-    }
+  /**
+   * Get the {@link BindingTuple}.
+   */
+  default BindingTuple bindingTuples() {
+    return BindingTuple.EMPTY;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtils.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtils.java
index fb4ecdc9cd..b0cc193ef5 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtils.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtils.java
@@ -15,153 +15,166 @@
 
 package com.amazon.opendistroforelasticsearch.sql.data.model;
 
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.ARRAY;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.BOOLEAN;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.STRING;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.STRUCT;
+
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
 import com.google.common.annotations.VisibleForTesting;
-import java.util.LinkedHashMap;
-import lombok.experimental.UtilityClass;
-
 import java.util.ArrayList;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
-
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.ARRAY;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.BOOLEAN;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.STRING;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.STRUCT;
+import lombok.experimental.UtilityClass;
 
 /**
  * The definition of {@link ExprValue} factory.
  */
 @UtilityClass
 public class ExprValueUtils {
-    public static final ExprValue LITERAL_TRUE = ExprBooleanValue.ofTrue();
-    public static final ExprValue LITERAL_FALSE = ExprBooleanValue.ofFalse();
-    public static final ExprValue LITERAL_NULL = ExprNullValue.of();
-    public static final ExprValue LITERAL_MISSING = ExprMissingValue.of();
-
-    public static ExprValue booleanValue(Boolean value) {
-        return value ? LITERAL_TRUE : LITERAL_FALSE;
-    }
-
-    public static ExprValue integerValue(Integer value) {
-        return new ExprIntegerValue(value);
-    }
-
-    public static ExprValue doubleValue(Double value) {
-        return new ExprDoubleValue(value);
-    }
-
-    public static ExprValue floatValue(Float value) {
-        return new ExprFloatValue(value);
-    }
-
-    public static ExprValue longValue(Long value) {
-        return new ExprLongValue(value);
-    }
-
-    public static ExprValue stringValue(String value) {
-        return new ExprStringValue(value);
-    }
-
-    public static ExprValue tupleValue(Map<String, Object> map) {
-        LinkedHashMap<String, ExprValue> valueMap = new LinkedHashMap<>();
-        map.forEach((k, v) -> valueMap.put(k, fromObjectValue(v)));
-        return new ExprTupleValue(valueMap);
-    }
-
-    public static ExprValue collectionValue(List<Object> list) {
-        List<ExprValue> valueList = new ArrayList<>();
-        list.forEach(o -> valueList.add(fromObjectValue(o)));
-        return new ExprCollectionValue(valueList);
-    }
-
-    public static ExprValue missingValue() {
-        return ExprMissingValue.of();
-    }
-
-    public static ExprValue nullValue() {
-        return ExprNullValue.of();
-    }
-
-    public static ExprValue fromObjectValue(Object o) {
-        if ( null == o) {
-            return LITERAL_NULL;
-        }
-        if (o instanceof Map) {
-            return tupleValue((Map) o);
-        } else if (o instanceof List) {
-            return collectionValue(((List) o));
-        } else if (o instanceof Integer) {
-            return integerValue((Integer) o);
-        } else if (o instanceof Long) {
-            return longValue(((Long) o));
-        } else if (o instanceof Boolean) {
-            return booleanValue((Boolean) o);
-        } else if (o instanceof Double) {
-            return doubleValue((Double) o);
-        } else if (o instanceof String) {
-            return stringValue((String) o);
-        } else if (o instanceof Float) {
-            return floatValue((Float) o);
-        } else {
-            throw new ExpressionEvaluationException("unsupported object " + o.getClass());
-        }
-    }
-
-    public static Integer getIntegerValue(ExprValue exprValue) {
-        return getNumberValue(exprValue).intValue();
-    }
-
-    public static Double getDoubleValue(ExprValue exprValue) {
-        return getNumberValue(exprValue).doubleValue();
-    }
-
-    public static Long getLongValue(ExprValue exprValue) {
-        return getNumberValue(exprValue).longValue();
-    }
-
-    public static Float getFloatValue(ExprValue exprValue) {
-        return getNumberValue(exprValue).floatValue();
-    }
-
-    public static String getStringValue(ExprValue exprValue) {
-        return convert(exprValue, STRING);
-    }
-
-    public static List<ExprValue> getCollectionValue(ExprValue exprValue) {
-        return convert(exprValue, ARRAY);
-    }
-
-    public static Map<String, ExprValue> getTupleValue(ExprValue exprValue) {
-        return convert(exprValue, STRUCT);
-    }
-
-    public static Boolean getBooleanValue(ExprValue exprValue) {
-        return convert(exprValue, BOOLEAN);
-    }
-
-    @VisibleForTesting
-    public static Number getNumberValue(ExprValue exprValue) {
-        switch (exprValue.type()) {
-            case INTEGER:
-            case DOUBLE:
-            case LONG:
-            case FLOAT:
-                return (Number) exprValue.value();
-            default:
-                break;
-        }
-        throw new ExpressionEvaluationException(
-                String.format("invalid to getNumberValue with expression has type of %s", exprValue.type()));
-    }
-
-    @SuppressWarnings("unchecked")
-    private static <T> T convert(ExprValue exprValue, ExprType toType) {
-        if (exprValue.type() == toType) {
-            return (T) exprValue.value();
-        } else {
-            throw new ExpressionEvaluationException(
-                    String.format("invalid to convert expression with type:%s to type:%s", exprValue.type(), toType));
-        }
-    }
+  public static final ExprValue LITERAL_TRUE = ExprBooleanValue.ofTrue();
+  public static final ExprValue LITERAL_FALSE = ExprBooleanValue.ofFalse();
+  public static final ExprValue LITERAL_NULL = ExprNullValue.of();
+  public static final ExprValue LITERAL_MISSING = ExprMissingValue.of();
+
+  public static ExprValue booleanValue(Boolean value) {
+    return value ? LITERAL_TRUE : LITERAL_FALSE;
+  }
+
+  public static ExprValue integerValue(Integer value) {
+    return new ExprIntegerValue(value);
+  }
+
+  public static ExprValue doubleValue(Double value) {
+    return new ExprDoubleValue(value);
+  }
+
+  public static ExprValue floatValue(Float value) {
+    return new ExprFloatValue(value);
+  }
+
+  public static ExprValue longValue(Long value) {
+    return new ExprLongValue(value);
+  }
+
+  public static ExprValue stringValue(String value) {
+    return new ExprStringValue(value);
+  }
+
+  /**
+   * {@link ExprTupleValue} constructor.
+   */
+  public static ExprValue tupleValue(Map<String, Object> map) {
+    LinkedHashMap<String, ExprValue> valueMap = new LinkedHashMap<>();
+    map.forEach((k, v) -> valueMap.put(k, fromObjectValue(v)));
+    return new ExprTupleValue(valueMap);
+  }
+
+  /**
+   * {@link ExprCollectionValue} constructor.
+   */
+  public static ExprValue collectionValue(List<Object> list) {
+    List<ExprValue> valueList = new ArrayList<>();
+    list.forEach(o -> valueList.add(fromObjectValue(o)));
+    return new ExprCollectionValue(valueList);
+  }
+
+  public static ExprValue missingValue() {
+    return ExprMissingValue.of();
+  }
+
+  public static ExprValue nullValue() {
+    return ExprNullValue.of();
+  }
+
+  /**
+   * Construct ExprValue from Object.
+   */
+  public static ExprValue fromObjectValue(Object o) {
+    if (null == o) {
+      return LITERAL_NULL;
+    }
+    if (o instanceof Map) {
+      return tupleValue((Map) o);
+    } else if (o instanceof List) {
+      return collectionValue(((List) o));
+    } else if (o instanceof Integer) {
+      return integerValue((Integer) o);
+    } else if (o instanceof Long) {
+      return longValue(((Long) o));
+    } else if (o instanceof Boolean) {
+      return booleanValue((Boolean) o);
+    } else if (o instanceof Double) {
+      return doubleValue((Double) o);
+    } else if (o instanceof String) {
+      return stringValue((String) o);
+    } else if (o instanceof Float) {
+      return floatValue((Float) o);
+    } else {
+      throw new ExpressionEvaluationException("unsupported object " + o.getClass());
+    }
+  }
+
+  public static Integer getIntegerValue(ExprValue exprValue) {
+    return getNumberValue(exprValue).intValue();
+  }
+
+  public static Double getDoubleValue(ExprValue exprValue) {
+    return getNumberValue(exprValue).doubleValue();
+  }
+
+  public static Long getLongValue(ExprValue exprValue) {
+    return getNumberValue(exprValue).longValue();
+  }
+
+  public static Float getFloatValue(ExprValue exprValue) {
+    return getNumberValue(exprValue).floatValue();
+  }
+
+  public static String getStringValue(ExprValue exprValue) {
+    return convert(exprValue, STRING);
+  }
+
+  public static List<ExprValue> getCollectionValue(ExprValue exprValue) {
+    return convert(exprValue, ARRAY);
+  }
+
+  public static Map<String, ExprValue> getTupleValue(ExprValue exprValue) {
+    return convert(exprValue, STRUCT);
+  }
+
+  public static Boolean getBooleanValue(ExprValue exprValue) {
+    return convert(exprValue, BOOLEAN);
+  }
+
+  /**
+   * Get Number Value from {@link ExprValue}.
+   */
+  @VisibleForTesting
+  public static Number getNumberValue(ExprValue exprValue) {
+    switch (exprValue.type()) {
+      case INTEGER:
+      case DOUBLE:
+      case LONG:
+      case FLOAT:
+        return (Number) exprValue.value();
+      default:
+        break;
+    }
+    throw new ExpressionEvaluationException(
+        String
+            .format("invalid to getNumberValue with expression has type of %s", exprValue.type()));
+  }
+
+  @SuppressWarnings("unchecked")
+  private static <T> T convert(ExprValue exprValue, ExprType toType) {
+    if (exprValue.type() == toType) {
+      return (T) exprValue.value();
+    } else {
+      throw new ExpressionEvaluationException(
+          String.format("invalid to convert expression with type:%s to type:%s", exprValue.type(),
+              toType));
+    }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NaturalExprValueOrdering.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NaturalExprValueOrdering.java
index 5d2e4dcc19..7d9616599d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NaturalExprValueOrdering.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NaturalExprValueOrdering.java
@@ -71,9 +71,10 @@ public int compare(ExprValue left, ExprValue right) {
         return MAP_COMPARATOR.apply(getTupleValue(left), getTupleValue(right));
       case ARRAY:
         return LIST_COMPARATOR.apply(getCollectionValue(left), getCollectionValue(right));
+      default:
+        throw new ExpressionEvaluationException(
+            String.format("compare doesn't support type [%s]", left.type()));
     }
-    throw new ExpressionEvaluationException(
-        String.format("compare doesn't support type [%s]", left.type()));
   }
 
   @Override
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/ExpressionEvaluationException.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/ExpressionEvaluationException.java
index 0b86891b31..040d0d522d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/ExpressionEvaluationException.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/ExpressionEvaluationException.java
@@ -19,7 +19,7 @@
  * Exception for Expression Evaluation.
  */
 public class ExpressionEvaluationException extends QueryEngineException {
-    public ExpressionEvaluationException(String message) {
-        super(message);
-    }
+  public ExpressionEvaluationException(String message) {
+    super(message);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/QueryEngineException.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/QueryEngineException.java
index 75c9d78b5e..2239d6e17c 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/QueryEngineException.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/QueryEngineException.java
@@ -20,7 +20,7 @@
  */
 public class QueryEngineException extends RuntimeException {
 
-    public QueryEngineException(String message) {
-        super(message);
-    }
+  public QueryEngineException(String message) {
+    super(message);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/SemanticCheckException.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/SemanticCheckException.java
index bd21ff4465..611e19d8c1 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/SemanticCheckException.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/exception/SemanticCheckException.java
@@ -19,7 +19,7 @@
  * Semantic Check Exception.
  */
 public class SemanticCheckException extends QueryEngineException {
-    public SemanticCheckException(String message) {
-        super(message);
-    }
+  public SemanticCheckException(String message) {
+    super(message);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/executor/ExecutionEngine.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/executor/ExecutionEngine.java
index 16d6f72f78..ec6e5bfbf2 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/executor/ExecutionEngine.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/executor/ExecutionEngine.java
@@ -19,28 +19,28 @@
 import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
-import lombok.Data;
-
 import java.util.List;
+import lombok.Data;
 
 /**
  * Execution engine that encapsulates execution details.
  */
 public interface ExecutionEngine {
 
-    /**
-     * Execute physical plan and call back response listener
-     * @param plan      executable physical plan
-     * @param listener  response listener
-     */
-    void execute(PhysicalPlan plan, ResponseListener<QueryResponse> listener);
+  /**
+   * Execute physical plan and call back response listener.
+   *
+   * @param plan     executable physical plan
+   * @param listener response listener
+   */
+  void execute(PhysicalPlan plan, ResponseListener<QueryResponse> listener);
 
-    /**
-     * Data class that encapsulates ExprValue
-     */
-    @Data
-    class QueryResponse {
-        private final List<ExprValue> results;
-    }
+  /**
+   * Data class that encapsulates ExprValue.
+   */
+  @Data
+  class QueryResponse {
+    private final List<ExprValue> results;
+  }
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/Expression.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/Expression.java
index 1f49b0afd9..3a0b9e7b4c 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/Expression.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/Expression.java
@@ -24,13 +24,13 @@
  */
 public interface Expression {
 
-    /**
-     * Evaluate the value of expression in the value environment
-     */
-    ExprValue valueOf(Environment<Expression, ExprValue> valueEnv);
+  /**
+   * Evaluate the value of expression in the value environment.
+   */
+  ExprValue valueOf(Environment<Expression, ExprValue> valueEnv);
 
-    /**
-     * Evaluate the type of expression in the type environment
-     */
-    ExprType type(Environment<Expression, ExprType> typeEnv);
+  /**
+   * Evaluate the type of expression in the type environment.
+   */
+  ExprType type(Environment<Expression, ExprType> typeEnv);
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/FunctionExpression.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/FunctionExpression.java
index e43a82192b..6271d7e0d1 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/FunctionExpression.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/FunctionExpression.java
@@ -17,21 +17,20 @@
 
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionImplementation;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionName;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
-import java.util.List;
-
 /**
- * Function Expression
+ * Function Expression.
  */
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public abstract class FunctionExpression implements Expression, FunctionImplementation {
-    @Getter
-    private final FunctionName functionName;
+  @Getter
+  private final FunctionName functionName;
 
-    @Getter
-    private final List<Expression> arguments;
+  @Getter
+  private final List<Expression> arguments;
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/LiteralExpression.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/LiteralExpression.java
index e6ae042e7a..40ecd71cbe 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/LiteralExpression.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/LiteralExpression.java
@@ -22,25 +22,25 @@
 import lombok.RequiredArgsConstructor;
 
 /**
- * Literal Expression
+ * Literal Expression.
  */
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LiteralExpression implements Expression {
-    private final ExprValue exprValue;
+  private final ExprValue exprValue;
 
-    @Override
-    public ExprValue valueOf(Environment<Expression, ExprValue> env) {
-        return exprValue;
-    }
+  @Override
+  public ExprValue valueOf(Environment<Expression, ExprValue> env) {
+    return exprValue;
+  }
 
-    @Override
-    public ExprType type(Environment<Expression, ExprType> env) {
-        return exprValue.type();
-    }
+  @Override
+  public ExprType type(Environment<Expression, ExprType> env) {
+    return exprValue.type();
+  }
 
-    @Override
-    public String toString() {
-        return exprValue.toString();
-    }
+  @Override
+  public String toString() {
+    return exprValue.toString();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpression.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpression.java
index 03eb384b0b..9186fb3f0b 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpression.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpression.java
@@ -25,21 +25,21 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class ReferenceExpression implements Expression {
-    @Getter
-    private final String attr;
+  @Getter
+  private final String attr;
 
-    @Override
-    public ExprValue valueOf(Environment<Expression, ExprValue> env) {
-        return env.resolve(this);
-    }
+  @Override
+  public ExprValue valueOf(Environment<Expression, ExprValue> env) {
+    return env.resolve(this);
+  }
 
-    @Override
-    public ExprType type(Environment<Expression, ExprType> env) {
-        return env.resolve(this);
-    }
+  @Override
+  public ExprType type(Environment<Expression, ExprType> env) {
+    return env.resolve(this);
+  }
 
-    @Override
-    public String toString() {
-        return attr;
-    }
+  @Override
+  public String toString() {
+    return attr;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationState.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationState.java
index 7a0a65c7d7..87f32d3f2c 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationState.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationState.java
@@ -22,8 +22,8 @@
  * Maintain the state when {@link Aggregator} iterate on the {@link BindingTuple}.
  */
 public interface AggregationState {
-    /**
-     * Get {@link ExprValue} result.
-     */
-    ExprValue result();
+  /**
+   * Get {@link ExprValue} result.
+   */
+  ExprValue result();
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/Aggregator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/Aggregator.java
index 79f80fe0fe..ea36b46a59 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/Aggregator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/Aggregator.java
@@ -24,47 +24,49 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionImplementation;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionName;
 import com.amazon.opendistroforelasticsearch.sql.storage.bindingtuple.BindingTuple;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
-import java.util.List;
-
 /**
  * Aggregator which will iterate on the {@link BindingTuple}s to aggregate the result.
  * The Aggregator is not well fit into Expression, because it has side effect.
- * But we still want to make it implement {@link Expression} interface to make {@link ExpressionAnalyzer} easier.
+ * But we still want to make it implement {@link Expression} interface to make
+ * {@link ExpressionAnalyzer} easier.
  */
 @EqualsAndHashCode
 @RequiredArgsConstructor
-public abstract class Aggregator<S extends AggregationState> implements FunctionImplementation, Expression {
-    @Getter
-    private final FunctionName functionName;
-    @Getter
-    private final List<Expression> arguments;
-    protected final ExprType returnType;
+public abstract class Aggregator<S extends AggregationState>
+    implements FunctionImplementation, Expression {
+  @Getter
+  private final FunctionName functionName;
+  @Getter
+  private final List<Expression> arguments;
+  protected final ExprType returnType;
 
-    /**
-     * Create an {@link AggregationState} which will be used for aggregation
-     */
-    public abstract S create();
+  /**
+   * Create an {@link AggregationState} which will be used for aggregation.
+   */
+  public abstract S create();
 
-    /**
-     * Iterate on the {@link BindingTuple}.
-     *
-     * @param tuple {@link BindingTuple}
-     * @param state {@link AggregationState}
-     * @return {@link AggregationState}
-     */
-    public abstract S iterate(BindingTuple tuple, S state);
+  /**
+   * Iterate on the {@link BindingTuple}.
+   *
+   * @param tuple {@link BindingTuple}
+   * @param state {@link AggregationState}
+   * @return {@link AggregationState}
+   */
+  public abstract S iterate(BindingTuple tuple, S state);
 
-    @Override
-    public ExprValue valueOf(Environment<Expression, ExprValue> valueEnv) {
-        throw new ExpressionEvaluationException(String.format("can't evaluate on aggregator: %s", functionName));
-    }
+  @Override
+  public ExprValue valueOf(Environment<Expression, ExprValue> valueEnv) {
+    throw new ExpressionEvaluationException(
+        String.format("can't evaluate on aggregator: %s", functionName));
+  }
 
-    @Override
-    public ExprType type(Environment<Expression, ExprType> typeEnv) {
-        return returnType;
-    }
+  @Override
+  public ExprType type(Environment<Expression, ExprType> typeEnv) {
+    return returnType;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregatorFunction.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregatorFunction.java
index 60ff968fde..079b0d2dc5 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregatorFunction.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregatorFunction.java
@@ -23,9 +23,8 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionResolver;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature;
 import com.google.common.collect.ImmutableMap;
-import lombok.experimental.UtilityClass;
-
 import java.util.Collections;
+import lombok.experimental.UtilityClass;
 
 /**
  * The definition of aggregator function
@@ -37,63 +36,66 @@
  */
 @UtilityClass
 public class AggregatorFunction {
+  /**
+   * Register Aggregation Function.
+   * @param repository {@link BuiltinFunctionRepository}.
+   */
+  public static void register(BuiltinFunctionRepository repository) {
+    repository.register(avg());
+    repository.register(sum());
+    repository.register(count());
+  }
 
-    public static void register(BuiltinFunctionRepository repository) {
-        repository.register(avg());
-        repository.register(sum());
-        repository.register(count());
-    }
-
-    private static FunctionResolver avg() {
-        FunctionName functionName = BuiltinFunctionName.AVG.getName();
-        return new FunctionResolver(
-                functionName,
-                new ImmutableMap.Builder<FunctionSignature, FunctionBuilder>()
-                        .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.DOUBLE)),
-                                arguments -> new AvgAggregator(arguments, ExprType.DOUBLE))
-                        .build()
-        );
-    }
+  private static FunctionResolver avg() {
+    FunctionName functionName = BuiltinFunctionName.AVG.getName();
+    return new FunctionResolver(
+        functionName,
+        new ImmutableMap.Builder<FunctionSignature, FunctionBuilder>()
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.DOUBLE)),
+                arguments -> new AvgAggregator(arguments, ExprType.DOUBLE))
+            .build()
+    );
+  }
 
-    private static FunctionResolver count() {
-        FunctionName functionName = BuiltinFunctionName.COUNT.getName();
-        return new FunctionResolver(
-            functionName,
-            new ImmutableMap.Builder<FunctionSignature, FunctionBuilder>()
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.INTEGER)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.LONG)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.FLOAT)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.DOUBLE)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.STRING)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.STRUCT)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.ARRAY)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.BOOLEAN)),
-                    arguments -> new CountAggregator(arguments, ExprType.INTEGER))
-                .build()
-        );
-    }
+  private static FunctionResolver count() {
+    FunctionName functionName = BuiltinFunctionName.COUNT.getName();
+    return new FunctionResolver(
+        functionName,
+        new ImmutableMap.Builder<FunctionSignature, FunctionBuilder>()
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.INTEGER)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.LONG)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.FLOAT)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.DOUBLE)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.STRING)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.STRUCT)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.ARRAY)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.BOOLEAN)),
+                arguments -> new CountAggregator(arguments, ExprType.INTEGER))
+            .build()
+    );
+  }
 
-    private static FunctionResolver sum() {
-        FunctionName functionName = BuiltinFunctionName.SUM.getName();
-        return new FunctionResolver(
-                functionName,
-                new ImmutableMap.Builder<FunctionSignature, FunctionBuilder>()
-                        .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.INTEGER)),
-                                arguments -> new SumAggregator(arguments, ExprType.INTEGER))
-                        .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.LONG)),
-                                arguments -> new SumAggregator(arguments, ExprType.LONG))
-                        .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.FLOAT)),
-                                arguments -> new SumAggregator(arguments, ExprType.FLOAT))
-                        .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.DOUBLE)),
-                                arguments -> new SumAggregator(arguments, ExprType.DOUBLE))
-                        .build()
-        );
-    }
+  private static FunctionResolver sum() {
+    FunctionName functionName = BuiltinFunctionName.SUM.getName();
+    return new FunctionResolver(
+        functionName,
+        new ImmutableMap.Builder<FunctionSignature, FunctionBuilder>()
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.INTEGER)),
+                arguments -> new SumAggregator(arguments, ExprType.INTEGER))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.LONG)),
+                arguments -> new SumAggregator(arguments, ExprType.LONG))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.FLOAT)),
+                arguments -> new SumAggregator(arguments, ExprType.FLOAT))
+            .put(new FunctionSignature(functionName, Collections.singletonList(ExprType.DOUBLE)),
+                arguments -> new SumAggregator(arguments, ExprType.DOUBLE))
+            .build()
+    );
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregator.java
index b7c95568a4..1dfb7008f4 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregator.java
@@ -15,6 +15,8 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.aggregation;
 
+import static com.amazon.opendistroforelasticsearch.sql.utils.ExpressionUtils.format;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprNullValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
@@ -22,61 +24,58 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.BuiltinFunctionName;
 import com.amazon.opendistroforelasticsearch.sql.storage.bindingtuple.BindingTuple;
-
 import java.util.List;
 import java.util.Locale;
 
-import static com.amazon.opendistroforelasticsearch.sql.utils.ExpressionUtils.format;
-
 /**
  * The average aggregator aggregate the value evaluated by the expression.
  * If the expression evaluated result is NULL or MISSING, then the result is NULL.
  */
 public class AvgAggregator extends Aggregator<AvgAggregator.AvgState> {
 
-    public AvgAggregator(List<Expression> arguments, ExprType returnType) {
-        super(BuiltinFunctionName.AVG.getName(), arguments, returnType);
-    }
+  public AvgAggregator(List<Expression> arguments, ExprType returnType) {
+    super(BuiltinFunctionName.AVG.getName(), arguments, returnType);
+  }
 
-    @Override
-    public AvgState create() {
-        return new AvgState();
-    }
+  @Override
+  public AvgState create() {
+    return new AvgState();
+  }
 
-    @Override
-    public AvgState iterate(BindingTuple tuple, AvgState state) {
-        Expression expression = getArguments().get(0);
-        ExprValue value = expression.valueOf(tuple);
-        if (value.isNull() || value.isMissing()) {
-            state.isNullResult = true;
-        } else {
-            state.count++;
-            state.total += ExprValueUtils.getDoubleValue(value);
-        }
-        return state;
+  @Override
+  public AvgState iterate(BindingTuple tuple, AvgState state) {
+    Expression expression = getArguments().get(0);
+    ExprValue value = expression.valueOf(tuple);
+    if (value.isNull() || value.isMissing()) {
+      state.isNullResult = true;
+    } else {
+      state.count++;
+      state.total += ExprValueUtils.getDoubleValue(value);
     }
+    return state;
+  }
 
-    @Override
-    public String toString() {
-        return String.format(Locale.ROOT, "avg(%s)", format(getArguments()));
-    }
+  @Override
+  public String toString() {
+    return String.format(Locale.ROOT, "avg(%s)", format(getArguments()));
+  }
 
-    /**
-     * Average State.
-     */
-    protected class AvgState implements AggregationState {
-        private int count;
-        private double total;
-        private boolean isNullResult = false;
+  /**
+   * Average State.
+   */
+  protected class AvgState implements AggregationState {
+    private int count;
+    private double total;
+    private boolean isNullResult = false;
 
-        public AvgState() {
-            this.count = 0;
-            this.total = 0d;
-        }
+    public AvgState() {
+      this.count = 0;
+      this.total = 0d;
+    }
 
-        @Override
-        public ExprValue result() {
-            return isNullResult ? ExprNullValue.of() : ExprValueUtils.doubleValue(total / count);
-        }
+    @Override
+    public ExprValue result() {
+      return isNullResult ? ExprNullValue.of() : ExprValueUtils.doubleValue(total / count);
     }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregator.java
index eeae8d1a20..f2de120fcf 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregator.java
@@ -53,7 +53,9 @@ public String toString() {
     return String.format(Locale.ROOT, "count(%s)", format(getArguments()));
   }
 
-  /** Count State. */
+  /**
+   * Count State.
+   */
   protected class CountState implements AggregationState {
     private int count;
 
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregator.java
index 00212cafb6..2285694e7d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregator.java
@@ -43,72 +43,72 @@
  */
 public class SumAggregator extends Aggregator<SumState> {
 
-    public SumAggregator(List<Expression> arguments, ExprType returnType) {
-        super(BuiltinFunctionName.SUM.getName(), arguments, returnType);
-    }
+  public SumAggregator(List<Expression> arguments, ExprType returnType) {
+    super(BuiltinFunctionName.SUM.getName(), arguments, returnType);
+  }
 
-    @Override
-    public SumState create() {
-        return new SumState(returnType);
-    }
+  @Override
+  public SumState create() {
+    return new SumState(returnType);
+  }
 
-    @Override
-    public SumState iterate(BindingTuple tuple, SumState state) {
-        Expression expression = getArguments().get(0);
-        ExprValue value = expression.valueOf(tuple);
-        if (value.isNull() || value.isMissing()) {
-            state.isNullResult = true;
-        } else {
-            state.add(value);
-        }
-        return state;
+  @Override
+  public SumState iterate(BindingTuple tuple, SumState state) {
+    Expression expression = getArguments().get(0);
+    ExprValue value = expression.valueOf(tuple);
+    if (value.isNull() || value.isMissing()) {
+      state.isNullResult = true;
+    } else {
+      state.add(value);
     }
+    return state;
+  }
 
-    @Override
-    public String toString() {
-        return String.format(Locale.ROOT, "sum(%s)", format(getArguments()));
-    }
+  @Override
+  public String toString() {
+    return String.format(Locale.ROOT, "sum(%s)", format(getArguments()));
+  }
 
-    /**
-     * Sum State.
-     */
-    protected class SumState implements AggregationState {
+  /**
+   * Sum State.
+   */
+  protected class SumState implements AggregationState {
 
-        private final ExprType type;
-        private ExprValue sumResult;
-        private boolean isNullResult = false;
+    private final ExprType type;
+    private ExprValue sumResult;
+    private boolean isNullResult = false;
 
-        public SumState(ExprType type) {
-            this.type = type;
-            sumResult = ExprValueUtils.integerValue(0);
-        }
+    public SumState(ExprType type) {
+      this.type = type;
+      sumResult = ExprValueUtils.integerValue(0);
+    }
 
-        /**
-         * Add value to current sumResult
-         */
-        public void add(ExprValue value) {
-            switch (type) {
-                case INTEGER:
-                    sumResult = integerValue(getIntegerValue(sumResult) + getIntegerValue(value));
-                    break;
-                case LONG:
-                    sumResult = longValue(getLongValue(sumResult) + getLongValue(value));
-                    break;
-                case FLOAT:
-                    sumResult = floatValue(getFloatValue(sumResult) + getFloatValue(value));
-                    break;
-                case DOUBLE:
-                    sumResult = doubleValue(getDoubleValue(sumResult) + getDoubleValue(value));
-                    break;
-                default:
-                    throw new ExpressionEvaluationException(
-                            String.format("unexpected type [%s] in sum aggregation", type));
-            }
-        }
+    /**
+     * Add value to current sumResult.
+     */
+    public void add(ExprValue value) {
+      switch (type) {
+        case INTEGER:
+          sumResult = integerValue(getIntegerValue(sumResult) + getIntegerValue(value));
+          break;
+        case LONG:
+          sumResult = longValue(getLongValue(sumResult) + getLongValue(value));
+          break;
+        case FLOAT:
+          sumResult = floatValue(getFloatValue(sumResult) + getFloatValue(value));
+          break;
+        case DOUBLE:
+          sumResult = doubleValue(getDoubleValue(sumResult) + getDoubleValue(value));
+          break;
+        default:
+          throw new ExpressionEvaluationException(
+              String.format("unexpected type [%s] in sum aggregation", type));
+      }
+    }
 
-        @Override
-        public ExprValue result() {
-            return isNullResult ? ExprNullValue.of() : sumResult;
-        }
+    @Override
+    public ExprValue result() {
+      return isNullResult ? ExprNullValue.of() : sumResult;
     }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/config/ExpressionConfig.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/config/ExpressionConfig.java
index c81ef3625a..4b49faa3dd 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/config/ExpressionConfig.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/config/ExpressionConfig.java
@@ -22,14 +22,18 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.scalar.arthmetic.UnaryFunction;
 import com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate.BinaryPredicateFunction;
 import com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate.UnaryPredicateFunction;
+import java.util.HashMap;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
-import java.util.HashMap;
-
-/** Expression Config for Spring IoC. */
+/**
+ * Expression Config for Spring IoC.
+ */
 @Configuration
 public class ExpressionConfig {
+  /**
+   * BuiltinFunctionRepository constructor.
+   */
   @Bean
   public BuiltinFunctionRepository functionRepository() {
     BuiltinFunctionRepository builtinFunctionRepository =
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/env/Environment.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/env/Environment.java
index c8e182af6d..51ac2e0806 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/env/Environment.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/env/Environment.java
@@ -15,24 +15,30 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.env;
 
-/** The definition of the environment. */
-public interface Environment<Expr, Value> {
+/**
+ * The definition of the environment.
+ * @param <E>  the type of expression
+ * @param <V> the type of expression value
+ */
+public interface Environment<E, V> {
 
-  /** resolve the value of expression from the environment. */
-  Value resolve(Expr var);
+  /**
+   * resolve the value of expression from the environment.
+   */
+  V resolve(E var);
 
   /**
    * Extend the environment.
    *
-   * @param env environment
-   * @param expr expression.
-   * @param value expression value.
-   * @param <Expr> the type of expression
-   * @param <Value> the type of expression value
+   * @param env     environment
+   * @param expr    expression.
+   * @param value   expression value.
+   * @param <E>  the type of expression
+   * @param <V> the type of expression value
    * @return extended environment.
    */
-  static <Expr, Value> Environment<Expr, Value> extendEnv(
-      Environment<Expr, Value> env, Expr expr, Value value) {
+  static <E, V> Environment<E, V> extendEnv(
+      Environment<E, V> env, E expr, V value) {
     return var -> {
       if (var.equals(expr)) {
         return value;
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionName.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionName.java
index 29ecb26fd6..493a19ae5d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionName.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionName.java
@@ -1,13 +1,14 @@
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
 import com.google.common.collect.ImmutableMap;
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-
 import java.util.Map;
 import java.util.Optional;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
 
-/** Builtin Function Name */
+/**
+ * Builtin Function Name.
+ */
 @Getter
 @RequiredArgsConstructor
 public enum BuiltinFunctionName {
@@ -22,7 +23,7 @@ public enum BuiltinFunctionName {
   TOSTRING(FunctionName.of("tostring")),
 
   /**
-   * Operator
+   * Operator.
    */
   ADD(FunctionName.of("+")),
   SUBTRACT(FunctionName.of("-")),
@@ -31,7 +32,9 @@ public enum BuiltinFunctionName {
   MODULES(FunctionName.of("%")),
   EQUAL(FunctionName.of("=")),
 
-  /** Aggregation Function. */
+  /**
+   * Aggregation Function.
+   */
   AVG(FunctionName.of("avg")),
   SUM(FunctionName.of("sum")),
   COUNT(FunctionName.of("count"));
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepository.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepository.java
index d6ffe863a9..80c871b617 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepository.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepository.java
@@ -1,55 +1,53 @@
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
-
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.expression.env.Environment;
-import lombok.RequiredArgsConstructor;
-
 import java.util.List;
 import java.util.Map;
 import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
 
 /**
- * Builtin Function Repository
+ * Builtin Function Repository.
  */
 @RequiredArgsConstructor
 public class BuiltinFunctionRepository {
-    private final Map<FunctionName, FunctionResolver> functionResolverMap;
+  private final Map<FunctionName, FunctionResolver> functionResolverMap;
 
-    /**
-     * Register {@link FunctionResolver} to the Builtin Function Repository.
-     *
-     * @param resolver {@link FunctionResolver} to be registered
-     */
-    public void register(FunctionResolver resolver) {
-        functionResolverMap.put(resolver.getFunctionName(), resolver);
-    }
+  /**
+   * Register {@link FunctionResolver} to the Builtin Function Repository.
+   *
+   * @param resolver {@link FunctionResolver} to be registered
+   */
+  public void register(FunctionResolver resolver) {
+    functionResolverMap.put(resolver.getFunctionName(), resolver);
+  }
 
-    /**
-     * Compile FunctionExpression
-     */
-    public FunctionImplementation compile(FunctionName functionName, List<Expression> expressions,
-                                          Environment<Expression, ExprType> env) {
-        FunctionBuilder resolvedFunctionBuilder = resolve(new FunctionSignature(functionName,
-                expressions.stream().map(expression -> expression.type(env)).collect(Collectors.toList())));
-        return resolvedFunctionBuilder.apply(expressions);
-    }
+  /**
+   * Compile FunctionExpression.
+   */
+  public FunctionImplementation compile(FunctionName functionName, List<Expression> expressions,
+                                        Environment<Expression, ExprType> env) {
+    FunctionBuilder resolvedFunctionBuilder = resolve(new FunctionSignature(functionName,
+        expressions.stream().map(expression -> expression.type(env)).collect(Collectors.toList())));
+    return resolvedFunctionBuilder.apply(expressions);
+  }
 
-    /**
-     * Resolve the {@link FunctionBuilder} in Builtin Function Repository.
-     *
-     * @param functionSignature {@link FunctionSignature}
-     * @return {@link FunctionBuilder}
-     */
-    public FunctionBuilder resolve(FunctionSignature functionSignature) {
-        FunctionName functionName = functionSignature.getFunctionName();
-        if (functionResolverMap.containsKey(functionName)) {
-            return functionResolverMap.get(functionName).resolve(functionSignature);
-        } else {
-            throw new ExpressionEvaluationException(
-                    String.format("unsupported function name: %s", functionName.getFunctionName()));
-        }
+  /**
+   * Resolve the {@link FunctionBuilder} in Builtin Function Repository.
+   *
+   * @param functionSignature {@link FunctionSignature}
+   * @return {@link FunctionBuilder}
+   */
+  public FunctionBuilder resolve(FunctionSignature functionSignature) {
+    FunctionName functionName = functionSignature.getFunctionName();
+    if (functionResolverMap.containsKey(functionName)) {
+      return functionResolverMap.get(functionName).resolve(functionSignature);
+    } else {
+      throw new ExpressionEvaluationException(
+          String.format("unsupported function name: %s", functionName.getFunctionName()));
     }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionBuilder.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionBuilder.java
index 30a889b28e..16353bb73d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionBuilder.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionBuilder.java
@@ -16,19 +16,19 @@
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
-
 import java.util.List;
 
 /**
- * The definition of function which create {@link FunctionImplementation} from input {@link Expression} list.
+ * The definition of function which create {@link FunctionImplementation}
+ * from input {@link Expression} list.
  */
 public interface FunctionBuilder {
 
-    /**
-     * Create {@link FunctionImplementation} from input {@link Expression} list
-     *
-     * @param arguments {@link Expression} list
-     * @return {@link FunctionImplementation}
-     */
-    FunctionImplementation apply(List<Expression> arguments);
+  /**
+   * Create {@link FunctionImplementation} from input {@link Expression} list.
+   *
+   * @param arguments {@link Expression} list
+   * @return {@link FunctionImplementation}
+   */
+  FunctionImplementation apply(List<Expression> arguments);
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionImplementation.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionImplementation.java
index 852b0cc364..9236e3dfae 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionImplementation.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionImplementation.java
@@ -16,7 +16,6 @@
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
-
 import java.util.List;
 
 /**
@@ -24,13 +23,13 @@
  */
 public interface FunctionImplementation {
 
-    /**
-     * Get Function Name.
-     */
-    FunctionName getFunctionName();
+  /**
+   * Get Function Name.
+   */
+  FunctionName getFunctionName();
 
-    /**
-     * Get Function Arguments.
-     */
-    List<Expression> getArguments();
+  /**
+   * Get Function Arguments.
+   */
+  List<Expression> getArguments();
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionName.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionName.java
index 1b4eb06b56..a3611a0506 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionName.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionName.java
@@ -25,15 +25,15 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class FunctionName {
-    @Getter
-    private final String functionName;
+  @Getter
+  private final String functionName;
 
-    public static FunctionName of(String functionName) {
-        return new FunctionName(functionName);
-    }
+  public static FunctionName of(String functionName) {
+    return new FunctionName(functionName);
+  }
 
-    @Override
-    public String toString() {
-        return functionName;
-    }
+  @Override
+  public String toString() {
+    return functionName;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolver.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolver.java
index 0727d9ddea..7df7423c48 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolver.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolver.java
@@ -1,16 +1,15 @@
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
-import lombok.Builder;
-import lombok.Getter;
-import lombok.RequiredArgsConstructor;
-import lombok.Singular;
-
 import java.util.AbstractMap;
 import java.util.Map;
 import java.util.PriorityQueue;
 import java.util.Set;
 import java.util.stream.Collectors;
+import lombok.Builder;
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+import lombok.Singular;
 
 /**
  * The Function Resolver hold the overload {@link FunctionBuilder} implementation.
@@ -21,39 +20,40 @@
 @Builder
 @RequiredArgsConstructor
 public class FunctionResolver {
-    @Getter
-    private final FunctionName functionName;
-    @Singular("functionBundle")
-    private final Map<FunctionSignature, FunctionBuilder> functionBundle;
+  @Getter
+  private final FunctionName functionName;
+  @Singular("functionBundle")
+  private final Map<FunctionSignature, FunctionBuilder> functionBundle;
 
-    /**
-     * Resolve the {@link FunctionBuilder} by using input {@link FunctionSignature}.
-     * If found the {@link FunctionBuilder} exactly match the input {@link FunctionSignature}, return it.
-     * If applying the widening rule, found the most match one, return it.
-     * If nothing found, throw {@link ExpressionEvaluationException}
-     */
-    public FunctionBuilder resolve(FunctionSignature unresolvedSignature) {
-        PriorityQueue<Map.Entry<Integer, FunctionSignature>> functionMatchQueue = new PriorityQueue<>(
-                Map.Entry.comparingByKey());
+  /**
+   * Resolve the {@link FunctionBuilder} by using input {@link FunctionSignature}.
+   * If the {@link FunctionBuilder} exactly match the input {@link FunctionSignature}, return it.
+   * If applying the widening rule, found the most match one, return it.
+   * If nothing found, throw {@link ExpressionEvaluationException}
+   */
+  public FunctionBuilder resolve(FunctionSignature unresolvedSignature) {
+    PriorityQueue<Map.Entry<Integer, FunctionSignature>> functionMatchQueue = new PriorityQueue<>(
+        Map.Entry.comparingByKey());
 
-        for (FunctionSignature functionSignature : functionBundle.keySet()) {
-            functionMatchQueue.add(
-                    new AbstractMap.SimpleEntry<>(unresolvedSignature.match(functionSignature), functionSignature));
-        }
-        Map.Entry<Integer, FunctionSignature> bestMatchEntry = functionMatchQueue.peek();
-        if (FunctionSignature.NOT_MATCH.equals(bestMatchEntry.getKey())) {
-            throw new ExpressionEvaluationException(
-                    String.format("%s function expected %s, but get %s", functionName,
-                            formatFunctions(functionBundle.keySet()),
-                            unresolvedSignature.formatTypes()
-                    ));
-        } else {
-            return functionBundle.get(bestMatchEntry.getValue());
-        }
+    for (FunctionSignature functionSignature : functionBundle.keySet()) {
+      functionMatchQueue.add(
+          new AbstractMap.SimpleEntry<>(unresolvedSignature.match(functionSignature),
+              functionSignature));
     }
-
-    private String formatFunctions(Set<FunctionSignature> functionSignatures) {
-        return functionSignatures.stream().map(FunctionSignature::formatTypes)
-                .collect(Collectors.joining(",", "{", "}"));
+    Map.Entry<Integer, FunctionSignature> bestMatchEntry = functionMatchQueue.peek();
+    if (FunctionSignature.NOT_MATCH.equals(bestMatchEntry.getKey())) {
+      throw new ExpressionEvaluationException(
+          String.format("%s function expected %s, but get %s", functionName,
+              formatFunctions(functionBundle.keySet()),
+              unresolvedSignature.formatTypes()
+          ));
+    } else {
+      return functionBundle.get(bestMatchEntry.getValue());
     }
+  }
+
+  private String formatFunctions(Set<FunctionSignature> functionSignatures) {
+    return functionSignatures.stream().map(FunctionSignature::formatTypes)
+        .collect(Collectors.joining(",", "{", "}"));
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignature.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignature.java
index 7706c4571d..80f4a9444a 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignature.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignature.java
@@ -1,13 +1,12 @@
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import java.util.List;
+import java.util.stream.Collectors;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
-import java.util.List;
-import java.util.stream.Collectors;
-
 /**
  * Function signature is composed by function name and arguments list.
  */
@@ -15,44 +14,46 @@
 @RequiredArgsConstructor
 @EqualsAndHashCode
 public class FunctionSignature {
-    public static final Integer NOT_MATCH = Integer.MAX_VALUE;
-    public static final Integer EXACTLY_MATCH = 0;
-
-    private final FunctionName functionName;
-    private final List<ExprType> paramTypeList;
+  public static final Integer NOT_MATCH = Integer.MAX_VALUE;
+  public static final Integer EXACTLY_MATCH = 0;
 
-    /**
-     * calculate the function signature match degree.
-     *
-     * @return EXACTLY_MATCH: exactly match, NOT_MATCH: not match, by widening rule small number means better match.
-     */
-    public int match(FunctionSignature functionSignature) {
-        List<ExprType> functionTypeList = functionSignature.getParamTypeList();
-        if (!functionName.equals(functionSignature.getFunctionName())
-                || paramTypeList.size() != functionTypeList.size()) {
-            return NOT_MATCH;
-        }
+  private final FunctionName functionName;
+  private final List<ExprType> paramTypeList;
 
-        int matchDegree = EXACTLY_MATCH;
-        for (int i = 0; i < paramTypeList.size(); i++) {
-            ExprType paramType = paramTypeList.get(i);
-            ExprType funcType = functionTypeList.get(i);
-            int match = WideningTypeRule.distance(paramType, funcType);
-            if (match == WideningTypeRule.IMPOSSIBLE_WIDENING) {
-                return NOT_MATCH;
-            } else {
-                matchDegree += match;
-            }
-        }
-        return matchDegree;
+  /**
+   * calculate the function signature match degree.
+   *
+   * @return  EXACTLY_MATCH: exactly match
+   *          NOT_MATCH: not match
+   *          By widening rule, the small number means better match
+   */
+  public int match(FunctionSignature functionSignature) {
+    List<ExprType> functionTypeList = functionSignature.getParamTypeList();
+    if (!functionName.equals(functionSignature.getFunctionName())
+        || paramTypeList.size() != functionTypeList.size()) {
+      return NOT_MATCH;
     }
 
-    /**
-     * util function for formatted arguments list
-     */
-    public String formatTypes() {
-        return getParamTypeList().stream()
-                .map(Enum::toString)
-                .collect(Collectors.joining(",", "[", "]"));
+    int matchDegree = EXACTLY_MATCH;
+    for (int i = 0; i < paramTypeList.size(); i++) {
+      ExprType paramType = paramTypeList.get(i);
+      ExprType funcType = functionTypeList.get(i);
+      int match = WideningTypeRule.distance(paramType, funcType);
+      if (match == WideningTypeRule.IMPOSSIBLE_WIDENING) {
+        return NOT_MATCH;
+      } else {
+        matchDegree += match;
+      }
     }
+    return matchDegree;
+  }
+
+  /**
+   * util function for formatted arguments list.
+   */
+  public String formatTypes() {
+    return getParamTypeList().stream()
+        .map(Enum::toString)
+        .collect(Collectors.joining(",", "[", "]"));
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRule.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRule.java
index eba5e992f0..02b344ddba 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRule.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRule.java
@@ -15,13 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
-import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
-import com.google.common.collect.ImmutableMap;
-import lombok.experimental.UtilityClass;
-
-import java.util.Map;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.ARRAY;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.BOOLEAN;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.DOUBLE;
@@ -32,6 +25,12 @@
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.STRUCT;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.UNKNOWN;
 
+import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
+import com.google.common.collect.ImmutableMap;
+import java.util.Map;
+import lombok.experimental.UtilityClass;
+
 /**
  * The definition of widening type rule for expression value.
  * ExprType     Widens to data types
@@ -46,63 +45,65 @@
  */
 @UtilityClass
 public class WideningTypeRule {
-    public static final int IMPOSSIBLE_WIDENING = Integer.MAX_VALUE;
-    public static final int TYPE_EQUAL = 0;
+  public static final int IMPOSSIBLE_WIDENING = Integer.MAX_VALUE;
+  public static final int TYPE_EQUAL = 0;
 
-    private static final Map<ExprType, ExprType> typeToWidenParent;
+  private static final Map<ExprType, ExprType> typeToWidenParent;
 
-    static {
-        ImmutableMap.Builder<ExprType, ExprType> builder = new ImmutableMap.Builder<>();
-        builder.put(INTEGER, LONG);
-        builder.put(LONG, FLOAT);
-        builder.put(FLOAT, DOUBLE);
-        builder.put(DOUBLE, UNKNOWN);
-        builder.put(STRING, UNKNOWN);
-        builder.put(BOOLEAN, UNKNOWN);
-        builder.put(ARRAY, UNKNOWN);
-        builder.put(STRUCT, UNKNOWN);
-        typeToWidenParent = builder.build();
-    }
+  static {
+    ImmutableMap.Builder<ExprType, ExprType> builder = new ImmutableMap.Builder<>();
+    builder.put(INTEGER, LONG);
+    builder.put(LONG, FLOAT);
+    builder.put(FLOAT, DOUBLE);
+    builder.put(DOUBLE, UNKNOWN);
+    builder.put(STRING, UNKNOWN);
+    builder.put(BOOLEAN, UNKNOWN);
+    builder.put(ARRAY, UNKNOWN);
+    builder.put(STRUCT, UNKNOWN);
+    typeToWidenParent = builder.build();
+  }
 
-    /**
-     * The widening distance is calculated from the leaf to root.
-     * e.g. distance(INTEGER, FLOAT) = 2, but distance(FLOAT, INTEGER) =
-     *
-     * @param type1 widen from type
-     * @param type2 widen to type
-     * @return The widening distance when widen one type to another type.
-     */
-    public static int distance(ExprType type1, ExprType type2) {
-        return distance(type1, type2, TYPE_EQUAL);
-    }
+  /**
+   * The widening distance is calculated from the leaf to root.
+   * e.g. distance(INTEGER, FLOAT) = 2, but distance(FLOAT, INTEGER) =
+   *
+   * @param type1 widen from type
+   * @param type2 widen to type
+   * @return The widening distance when widen one type to another type.
+   */
+  public static int distance(ExprType type1, ExprType type2) {
+    return distance(type1, type2, TYPE_EQUAL);
+  }
 
-    private static int distance(ExprType type1, ExprType type2, int distance) {
-        if (type1 == UNKNOWN) {
-            return IMPOSSIBLE_WIDENING;
-        } else if (type1 == type2) {
-            return distance;
-        } else {
-            return distance(typeToWidenParent.get(type1), type2, distance + 1);
-        }
+  private static int distance(ExprType type1, ExprType type2, int distance) {
+    if (type1 == UNKNOWN) {
+      return IMPOSSIBLE_WIDENING;
+    } else if (type1 == type2) {
+      return distance;
+    } else {
+      return distance(typeToWidenParent.get(type1), type2, distance + 1);
     }
+  }
 
-    /**
-     * The max type among two types. The max is defined as follow
-     * if type1 could widen to type2, then max is type2, vice versa
-     * if type1 could't widen to type2 and type2 could't widen to type1, then throw {@link ExpressionEvaluationException}
-     *
-     * @param type1 type1
-     * @param type2 type2
-     * @return the max type among two types.
-     */
-    public static ExprType max(ExprType type1, ExprType type2) {
-        int type1To2 = distance(type1, type2);
-        int type2To1 = distance(type2, type1);
+  /**
+   * The max type among two types. The max is defined as follow
+   * if type1 could widen to type2, then max is type2, vice versa
+   * if type1 could't widen to type2 and type2 could't widen to type1,
+   * then throw {@link ExpressionEvaluationException}.
+   *
+   * @param type1 type1
+   * @param type2 type2
+   * @return the max type among two types.
+   */
+  public static ExprType max(ExprType type1, ExprType type2) {
+    int type1To2 = distance(type1, type2);
+    int type2To1 = distance(type2, type1);
 
-        if (type1To2 == Integer.MAX_VALUE && type2To1 == Integer.MAX_VALUE) {
-            throw new ExpressionEvaluationException(String.format("no max type of %s and %s ", type1, type2));
-        } else {
-            return type1To2 == Integer.MAX_VALUE ? type1 : type2;
-        }
+    if (type1To2 == Integer.MAX_VALUE && type2To1 == Integer.MAX_VALUE) {
+      throw new ExpressionEvaluationException(
+          String.format("no max type of %s and %s ", type1, type2));
+    } else {
+      return type1To2 == Integer.MAX_VALUE ? type1 : type2;
     }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/OperatorUtils.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/OperatorUtils.java
index 3bae857cc8..d4c20fe38d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/OperatorUtils.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/OperatorUtils.java
@@ -36,11 +36,11 @@ public class OperatorUtils {
    * Construct {@link FunctionBuilder} which call function with arguments produced by observer.
    *
    * @param functionName function name
-   * @param function {@link BiFunction}
-   * @param observer extract the value of type T from the first argument
-   * @param returnType return type
-   * @param <T> the type of the first and second argument to the function
-   * @param <R> the type of the result of the function
+   * @param function     {@link BiFunction}
+   * @param observer     extract the value of type T from the first argument
+   * @param returnType   return type
+   * @param <T>          the type of the first and second argument to the function
+   * @param <R>          the type of the result of the function
    * @return {@link FunctionBuilder}
    */
   public static <T, R> FunctionBuilder binaryOperator(
@@ -55,16 +55,16 @@ public static <T, R> FunctionBuilder binaryOperator(
    * Construct {@link FunctionBuilder} which call function with arguments produced by observer1 and
    * observer2 In general, if any operand evaluates to a MISSING value, the enclosing operator will
    * return MISSING; if none of operands evaluates to a MISSING value but there is an operand
-   * evaluates to a NULL value, the enclosing operator will return NULL
+   * evaluates to a NULL value, the enclosing operator will return NULL.
    *
    * @param functionName function name
-   * @param function {@link BiFunction}
-   * @param observer1 extract the value of type T from the first argument
-   * @param observer2 extract the value of type U from the second argument
-   * @param returnType return type
-   * @param <T> the type of the first argument to the function
-   * @param <U> the type of the second argument to the function
-   * @param <R> the type of the result of the function
+   * @param function     {@link BiFunction}
+   * @param observer1    extract the value of type T from the first argument
+   * @param observer2    extract the value of type U from the second argument
+   * @param returnType   return type
+   * @param <T>          the type of the first argument to the function
+   * @param <U>          the type of the second argument to the function
+   * @param <R>          the type of the result of the function
    * @return {@link FunctionBuilder}
    */
   public static <T, U, R> FunctionBuilder binaryOperator(
@@ -100,14 +100,14 @@ public ExprType type(Environment<Expression, ExprType> env) {
    * Construct {@link FunctionBuilder} which call function with arguments produced by observer In
    * general, if any operand evaluates to a MISSING value, the enclosing operator will return
    * MISSING; if none of operands evaluates to a MISSING value but there is an operand evaluates to
-   * a NULL value, the enclosing operator will return NULL
+   * a NULL value, the enclosing operator will return NULL.
    *
    * @param functionName function name
-   * @param function {@link Function}
-   * @param observer extract the value of type T from the first argument
-   * @param returnType return type
-   * @param <T> the type of the first argument to the function
-   * @param <R> the type of the result of the function
+   * @param function     {@link Function}
+   * @param observer     extract the value of type T from the first argument
+   * @param returnType   return type
+   * @param <T>          the type of the first argument to the function
+   * @param <R>          the type of the result of the function
    * @return {@link FunctionBuilder}
    */
   public static <T, R> FunctionBuilder unaryOperator(
@@ -136,15 +136,23 @@ public ExprType type(Environment<Expression, ExprType> env) {
         };
   }
 
-  /** String comparator */
+  /**
+   * String comparator.
+   */
   public static final BiFunction<String, String, Integer> STRING_COMPARATOR = String::compareTo;
-  /** List comparator */
+  /**
+   * List comparator.
+   */
   public static final BiFunction<List, List, Integer> LIST_COMPARATOR =
       (left, right) -> Integer.compare(left.size(), right.size());
-  /** Map comparator */
+  /**
+   * Map comparator.
+   */
   public static final BiFunction<Map, Map, Integer> MAP_COMPARATOR =
       (left, right) -> Integer.compare(left.size(), right.size());
-  /** Predicate NULL or MISSING */
+  /**
+   * Predicate NULL or MISSING.
+   */
   public static final BiPredicate<ExprValue, ExprValue> COMPARE_WITH_NULL_OR_MISSING =
       (left, right) -> left.isMissing() || right.isMissing() || left.isNull() || right.isNull();
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunction.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunction.java
index c409b76fc0..a949d68c5d 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunction.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunction.java
@@ -15,6 +15,8 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.scalar.arthmetic;
 
+import static com.amazon.opendistroforelasticsearch.sql.expression.scalar.OperatorUtils.binaryOperator;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.BuiltinFunctionName;
@@ -24,13 +26,10 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionResolver;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature;
 import com.google.common.collect.ImmutableMap;
-import lombok.experimental.UtilityClass;
-
 import java.util.Arrays;
 import java.util.Map;
 import java.util.function.BiFunction;
-
-import static com.amazon.opendistroforelasticsearch.sql.expression.scalar.OperatorUtils.binaryOperator;
+import lombok.experimental.UtilityClass;
 
 /**
  * The definition of arithmetic function
@@ -42,86 +41,93 @@
  */
 @UtilityClass
 public class ArithmeticFunction {
+  /**
+   * Register Arithmetic Function.
+   * @param repository {@link BuiltinFunctionRepository}.
+   */
+  public static void register(BuiltinFunctionRepository repository) {
+    repository.register(add());
+    repository.register(subtract());
+    repository.register(multiply());
+    repository.register(divide());
+    repository.register(modules());
+  }
 
-    public static void register(BuiltinFunctionRepository repository) {
-        repository.register(add());
-        repository.register(subtract());
-        repository.register(multiply());
-        repository.register(divide());
-        repository.register(modules());
-    }
-
-    private static FunctionResolver add() {
-        return new FunctionResolver(
-                BuiltinFunctionName.ADD.getName(),
-                scalarFunction(BuiltinFunctionName.ADD.getName(),
-                        Math::addExact,
-                        Math::addExact,
-                        Float::sum,
-                        Double::sum)
-        );
-    }
+  private static FunctionResolver add() {
+    return new FunctionResolver(
+        BuiltinFunctionName.ADD.getName(),
+        scalarFunction(BuiltinFunctionName.ADD.getName(),
+            Math::addExact,
+            Math::addExact,
+            Float::sum,
+            Double::sum)
+    );
+  }
 
-    private static FunctionResolver subtract() {
-        return new FunctionResolver(
-                BuiltinFunctionName.SUBTRACT.getName(),
-                scalarFunction(BuiltinFunctionName.SUBTRACT.getName(),
-                        Math::subtractExact,
-                        Math::subtractExact,
-                        (v1, v2) -> v1 - v2,
-                        (v1, v2) -> v1 - v2)
-        );
-    }
+  private static FunctionResolver subtract() {
+    return new FunctionResolver(
+        BuiltinFunctionName.SUBTRACT.getName(),
+        scalarFunction(BuiltinFunctionName.SUBTRACT.getName(),
+            Math::subtractExact,
+            Math::subtractExact,
+            (v1, v2) -> v1 - v2,
+            (v1, v2) -> v1 - v2)
+    );
+  }
 
-    private static FunctionResolver multiply() {
-        return new FunctionResolver(
-                BuiltinFunctionName.MULTIPLY.getName(),
-                scalarFunction(BuiltinFunctionName.MULTIPLY.getName(),
-                        Math::multiplyExact,
-                        Math::multiplyExact,
-                        (v1, v2) -> v1 * v2,
-                        (v1, v2) -> v1 * v2)
-        );
-    }
+  private static FunctionResolver multiply() {
+    return new FunctionResolver(
+        BuiltinFunctionName.MULTIPLY.getName(),
+        scalarFunction(BuiltinFunctionName.MULTIPLY.getName(),
+            Math::multiplyExact,
+            Math::multiplyExact,
+            (v1, v2) -> v1 * v2,
+            (v1, v2) -> v1 * v2)
+    );
+  }
 
-    private static FunctionResolver divide() {
-        return new FunctionResolver(
-                BuiltinFunctionName.DIVIDE.getName(),
-                scalarFunction(BuiltinFunctionName.DIVIDE.getName(),
-                        (v1, v2) -> v1 / v2,
-                        (v1, v2) -> v1 / v2,
-                        (v1, v2) -> v1 / v2,
-                        (v1, v2) -> v1 / v2)
-        );
-    }
+  private static FunctionResolver divide() {
+    return new FunctionResolver(
+        BuiltinFunctionName.DIVIDE.getName(),
+        scalarFunction(BuiltinFunctionName.DIVIDE.getName(),
+            (v1, v2) -> v1 / v2,
+            (v1, v2) -> v1 / v2,
+            (v1, v2) -> v1 / v2,
+            (v1, v2) -> v1 / v2)
+    );
+  }
 
 
-    private static FunctionResolver modules() {
-        return new FunctionResolver(
-                BuiltinFunctionName.MODULES.getName(),
-                scalarFunction(BuiltinFunctionName.MODULES.getName(),
-                        (v1, v2) -> v1 % v2,
-                        (v1, v2) -> v1 % v2,
-                        (v1, v2) -> v1 % v2,
-                        (v1, v2) -> v1 % v2)
-        );
-    }
+  private static FunctionResolver modules() {
+    return new FunctionResolver(
+        BuiltinFunctionName.MODULES.getName(),
+        scalarFunction(BuiltinFunctionName.MODULES.getName(),
+            (v1, v2) -> v1 % v2,
+            (v1, v2) -> v1 % v2,
+            (v1, v2) -> v1 % v2,
+            (v1, v2) -> v1 % v2)
+    );
+  }
 
-    private static Map<FunctionSignature, FunctionBuilder> scalarFunction(
-            FunctionName functionName,
-            BiFunction<Integer, Integer, Integer> integerFunc,
-            BiFunction<Long, Long, Long> longFunc,
-            BiFunction<Float, Float, Float> floatFunc,
-            BiFunction<Double, Double, Double> doubleFunc) {
-        ImmutableMap.Builder<FunctionSignature, FunctionBuilder> builder = new ImmutableMap.Builder<>();
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.INTEGER, ExprType.INTEGER)),
-                binaryOperator(functionName, integerFunc, ExprValueUtils::getIntegerValue, ExprType.INTEGER));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.LONG, ExprType.LONG)),
-                binaryOperator(functionName, longFunc, ExprValueUtils::getLongValue, ExprType.LONG));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.FLOAT, ExprType.FLOAT)),
-                binaryOperator(functionName, floatFunc, ExprValueUtils::getFloatValue, ExprType.FLOAT));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.DOUBLE, ExprType.DOUBLE)),
-                binaryOperator(functionName, doubleFunc, ExprValueUtils::getDoubleValue, ExprType.DOUBLE));
-        return builder.build();
-    }
+  private static Map<FunctionSignature, FunctionBuilder> scalarFunction(
+      FunctionName functionName,
+      BiFunction<Integer, Integer, Integer> integerFunc,
+      BiFunction<Long, Long, Long> longFunc,
+      BiFunction<Float, Float, Float> floatFunc,
+      BiFunction<Double, Double, Double> doubleFunc) {
+    ImmutableMap.Builder<FunctionSignature, FunctionBuilder> builder = new ImmutableMap.Builder<>();
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.INTEGER, ExprType.INTEGER)),
+            binaryOperator(functionName, integerFunc, ExprValueUtils::getIntegerValue,
+                ExprType.INTEGER));
+    builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.LONG, ExprType.LONG)),
+        binaryOperator(functionName, longFunc, ExprValueUtils::getLongValue, ExprType.LONG));
+    builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.FLOAT, ExprType.FLOAT)),
+        binaryOperator(functionName, floatFunc, ExprValueUtils::getFloatValue, ExprType.FLOAT));
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.DOUBLE, ExprType.DOUBLE)),
+            binaryOperator(functionName, doubleFunc, ExprValueUtils::getDoubleValue,
+                ExprType.DOUBLE));
+    return builder.build();
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunction.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunction.java
index e1e962aad7..67d01b63d1 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunction.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunction.java
@@ -15,6 +15,11 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate;
 
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_FALSE;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
@@ -30,265 +35,269 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableTable;
 import com.google.common.collect.Table;
-import lombok.experimental.UtilityClass;
-
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.function.BiFunction;
 import java.util.function.Function;
-
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_FALSE;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
+import lombok.experimental.UtilityClass;
 
 /**
  * The definition of binary predicate function
  * and, Accepts two Boolean values and produces a Boolean.
  * or,  Accepts two Boolean values and produces a Boolean.
  * xor, Accepts two Boolean values and produces a Boolean.
- * equal, Compare the left expression and right expression and produces a Boolean.
+ * equalTo, Compare the left expression and right expression and produces a Boolean.
  */
 @UtilityClass
 public class BinaryPredicateFunction {
-    public static void register(BuiltinFunctionRepository repository) {
-        repository.register(and());
-        repository.register(or());
-        repository.register(xor());
-        repository.register(equal());
-    }
+  /**
+   * Register Binary Predicate Function.
+   *
+   * @param repository {@link BuiltinFunctionRepository}.
+   */
+  public static void register(BuiltinFunctionRepository repository) {
+    repository.register(and());
+    repository.register(or());
+    repository.register(xor());
+    repository.register(equal());
+  }
 
-    /**
-     * The and logic
-     * A       B       A AND B
-     * TRUE    TRUE    TRUE
-     * TRUE    FALSE   FALSE
-     * TRUE    NULL    NULL
-     * TRUE    MISSING MISSING
-     * FALSE   FALSE   FALSE
-     * FALSE   NULL    FALSE
-     * FALSE   MISSING FALSE
-     * NULL    NULL    NULL
-     * NULL    MISSING MISSING
-     * MISSING MISSING MISSING
-     */
-    private static Table<ExprValue, ExprValue, ExprValue> andTable =
-            new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
-                    .put(LITERAL_TRUE, LITERAL_TRUE, LITERAL_TRUE)
-                    .put(LITERAL_TRUE, LITERAL_FALSE, LITERAL_FALSE)
-                    .put(LITERAL_TRUE, LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_TRUE, LITERAL_MISSING, LITERAL_MISSING)
-                    .put(LITERAL_FALSE, LITERAL_FALSE, LITERAL_FALSE)
-                    .put(LITERAL_FALSE, LITERAL_NULL, LITERAL_FALSE)
-                    .put(LITERAL_FALSE, LITERAL_MISSING, LITERAL_FALSE)
-                    .put(LITERAL_NULL, LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_MISSING)
-                    .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_MISSING)
-                    .build();
+  /**
+   * The and logic.
+   * A       B       A AND B
+   * TRUE    TRUE    TRUE
+   * TRUE    FALSE   FALSE
+   * TRUE    NULL    NULL
+   * TRUE    MISSING MISSING
+   * FALSE   FALSE   FALSE
+   * FALSE   NULL    FALSE
+   * FALSE   MISSING FALSE
+   * NULL    NULL    NULL
+   * NULL    MISSING MISSING
+   * MISSING MISSING MISSING
+   */
+  private static Table<ExprValue, ExprValue, ExprValue> andTable =
+      new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
+          .put(LITERAL_TRUE, LITERAL_TRUE, LITERAL_TRUE)
+          .put(LITERAL_TRUE, LITERAL_FALSE, LITERAL_FALSE)
+          .put(LITERAL_TRUE, LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_TRUE, LITERAL_MISSING, LITERAL_MISSING)
+          .put(LITERAL_FALSE, LITERAL_FALSE, LITERAL_FALSE)
+          .put(LITERAL_FALSE, LITERAL_NULL, LITERAL_FALSE)
+          .put(LITERAL_FALSE, LITERAL_MISSING, LITERAL_FALSE)
+          .put(LITERAL_NULL, LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_MISSING)
+          .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_MISSING)
+          .build();
 
-    /**
-     * The or logic
-     * A       B       A AND B
-     * TRUE    TRUE    TRUE
-     * TRUE    FALSE   TRUE
-     * TRUE    NULL    TRUE
-     * TRUE    MISSING TRUE
-     * FALSE   FALSE   FALSE
-     * FALSE   NULL    NULL
-     * FALSE   MISSING MISSING
-     * NULL    NULL    NULL
-     * NULL    MISSING NULL
-     * MISSING MISSING MISSING
-     */
-    private static Table<ExprValue, ExprValue, ExprValue> orTable =
-            new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
-                    .put(LITERAL_TRUE, LITERAL_TRUE, LITERAL_TRUE)
-                    .put(LITERAL_TRUE, LITERAL_FALSE, LITERAL_TRUE)
-                    .put(LITERAL_TRUE, LITERAL_NULL, LITERAL_TRUE)
-                    .put(LITERAL_TRUE, LITERAL_MISSING, LITERAL_TRUE)
-                    .put(LITERAL_FALSE, LITERAL_FALSE, LITERAL_FALSE)
-                    .put(LITERAL_FALSE, LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_FALSE, LITERAL_MISSING, LITERAL_MISSING)
-                    .put(LITERAL_NULL, LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_NULL)
-                    .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_MISSING)
-                    .build();
+  /**
+   * The or logic.
+   * A       B       A AND B
+   * TRUE    TRUE    TRUE
+   * TRUE    FALSE   TRUE
+   * TRUE    NULL    TRUE
+   * TRUE    MISSING TRUE
+   * FALSE   FALSE   FALSE
+   * FALSE   NULL    NULL
+   * FALSE   MISSING MISSING
+   * NULL    NULL    NULL
+   * NULL    MISSING NULL
+   * MISSING MISSING MISSING
+   */
+  private static Table<ExprValue, ExprValue, ExprValue> orTable =
+      new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
+          .put(LITERAL_TRUE, LITERAL_TRUE, LITERAL_TRUE)
+          .put(LITERAL_TRUE, LITERAL_FALSE, LITERAL_TRUE)
+          .put(LITERAL_TRUE, LITERAL_NULL, LITERAL_TRUE)
+          .put(LITERAL_TRUE, LITERAL_MISSING, LITERAL_TRUE)
+          .put(LITERAL_FALSE, LITERAL_FALSE, LITERAL_FALSE)
+          .put(LITERAL_FALSE, LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_FALSE, LITERAL_MISSING, LITERAL_MISSING)
+          .put(LITERAL_NULL, LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_NULL)
+          .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_MISSING)
+          .build();
 
-    /**
-     * The xor logic
-     * A       B       A AND B
-     * TRUE    TRUE    FALSE
-     * TRUE    FALSE   TRUE
-     * TRUE    NULL    TRUE
-     * TRUE    MISSING TRUE
-     * FALSE   FALSE   FALSE
-     * FALSE   NULL    NULL
-     * FALSE   MISSING MISSING
-     * NULL    NULL    NULL
-     * NULL    MISSING NULL
-     * MISSING MISSING MISSING
-     */
-    private static Table<ExprValue, ExprValue, ExprValue> xorTable =
-            new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
-                    .put(LITERAL_TRUE, LITERAL_TRUE, LITERAL_FALSE)
-                    .put(LITERAL_TRUE, LITERAL_FALSE, LITERAL_TRUE)
-                    .put(LITERAL_TRUE, LITERAL_NULL, LITERAL_TRUE)
-                    .put(LITERAL_TRUE, LITERAL_MISSING, LITERAL_TRUE)
-                    .put(LITERAL_FALSE, LITERAL_FALSE, LITERAL_FALSE)
-                    .put(LITERAL_FALSE, LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_FALSE, LITERAL_MISSING, LITERAL_MISSING)
-                    .put(LITERAL_NULL, LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_NULL)
-                    .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_MISSING)
-                    .build();
+  /**
+   * The xor logic.
+   * A       B       A AND B
+   * TRUE    TRUE    FALSE
+   * TRUE    FALSE   TRUE
+   * TRUE    NULL    TRUE
+   * TRUE    MISSING TRUE
+   * FALSE   FALSE   FALSE
+   * FALSE   NULL    NULL
+   * FALSE   MISSING MISSING
+   * NULL    NULL    NULL
+   * NULL    MISSING NULL
+   * MISSING MISSING MISSING
+   */
+  private static Table<ExprValue, ExprValue, ExprValue> xorTable =
+      new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
+          .put(LITERAL_TRUE, LITERAL_TRUE, LITERAL_FALSE)
+          .put(LITERAL_TRUE, LITERAL_FALSE, LITERAL_TRUE)
+          .put(LITERAL_TRUE, LITERAL_NULL, LITERAL_TRUE)
+          .put(LITERAL_TRUE, LITERAL_MISSING, LITERAL_TRUE)
+          .put(LITERAL_FALSE, LITERAL_FALSE, LITERAL_FALSE)
+          .put(LITERAL_FALSE, LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_FALSE, LITERAL_MISSING, LITERAL_MISSING)
+          .put(LITERAL_NULL, LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_NULL)
+          .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_MISSING)
+          .build();
 
-    /**
-     * The equal logic
-     * A       B       A == B
-     * NULL    NULL    TRUE
-     * NULL    MISSING FALSE
-     * MISSING NULL    FALSE
-     * MISSING MISSING TRUE
-     */
-    private static Table<ExprValue, ExprValue, ExprValue> equalTable =
-            new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
-                    .put(LITERAL_NULL, LITERAL_NULL, LITERAL_TRUE)
-                    .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_FALSE)
-                    .put(LITERAL_MISSING, LITERAL_NULL, LITERAL_FALSE)
-                    .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_TRUE)
-                    .build();
+  /**
+   * The equalTo logic.
+   * A       B       A == B
+   * NULL    NULL    TRUE
+   * NULL    MISSING FALSE
+   * MISSING NULL    FALSE
+   * MISSING MISSING TRUE
+   */
+  private static Table<ExprValue, ExprValue, ExprValue> equalTable =
+      new ImmutableTable.Builder<ExprValue, ExprValue, ExprValue>()
+          .put(LITERAL_NULL, LITERAL_NULL, LITERAL_TRUE)
+          .put(LITERAL_NULL, LITERAL_MISSING, LITERAL_FALSE)
+          .put(LITERAL_MISSING, LITERAL_NULL, LITERAL_FALSE)
+          .put(LITERAL_MISSING, LITERAL_MISSING, LITERAL_TRUE)
+          .build();
 
-    private static FunctionResolver and() {
-        FunctionName functionName = BuiltinFunctionName.AND.getName();
-        return FunctionResolver.builder()
-                .functionName(functionName)
-                .functionBundle(new FunctionSignature(functionName,
-                        Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)), binaryPredicate(functionName,
-                        andTable, ExprType.BOOLEAN))
-                .build();
-    }
+  private static FunctionResolver and() {
+    FunctionName functionName = BuiltinFunctionName.AND.getName();
+    return FunctionResolver.builder()
+        .functionName(functionName)
+        .functionBundle(new FunctionSignature(functionName,
+            Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)), binaryPredicate(functionName,
+            andTable, ExprType.BOOLEAN))
+        .build();
+  }
 
-    private static FunctionResolver or() {
-        FunctionName functionName = BuiltinFunctionName.OR.getName();
-        return FunctionResolver.builder()
-                .functionName(functionName)
-                .functionBundle(new FunctionSignature(functionName,
-                        Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)), binaryPredicate(functionName,
-                        orTable, ExprType.BOOLEAN))
-                .build();
-    }
+  private static FunctionResolver or() {
+    FunctionName functionName = BuiltinFunctionName.OR.getName();
+    return FunctionResolver.builder()
+        .functionName(functionName)
+        .functionBundle(new FunctionSignature(functionName,
+            Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)), binaryPredicate(functionName,
+            orTable, ExprType.BOOLEAN))
+        .build();
+  }
 
-    private static FunctionResolver xor() {
-        FunctionName functionName = BuiltinFunctionName.XOR.getName();
-        return FunctionResolver.builder()
-                .functionName(functionName)
-                .functionBundle(new FunctionSignature(functionName,
-                        Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)), binaryPredicate(functionName,
-                        xorTable, ExprType.BOOLEAN))
-                .build();
-    }
+  private static FunctionResolver xor() {
+    FunctionName functionName = BuiltinFunctionName.XOR.getName();
+    return FunctionResolver.builder()
+        .functionName(functionName)
+        .functionBundle(new FunctionSignature(functionName,
+            Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)), binaryPredicate(functionName,
+            xorTable, ExprType.BOOLEAN))
+        .build();
+  }
 
-    private static FunctionResolver equal() {
-        return new FunctionResolver(
-                BuiltinFunctionName.EQUAL.getName(),
-                predicateFunction(
-                        BuiltinFunctionName.EQUAL.getName(),
-                        Integer::equals,
-                        Long::equals,
-                        Float::equals,
-                        Double::equals,
-                        String::equals,
-                        Boolean::equals,
-                        List::equals,
-                        Map::equals
-                )
-        );
-    }
+  private static FunctionResolver equal() {
+    return new FunctionResolver(
+        BuiltinFunctionName.EQUAL.getName(),
+        predicateFunction(
+            BuiltinFunctionName.EQUAL.getName(),
+            Integer::equals,
+            Long::equals,
+            Float::equals,
+            Double::equals,
+            String::equals,
+            Boolean::equals,
+            List::equals,
+            Map::equals
+        )
+    );
+  }
 
-    private static Map<FunctionSignature, FunctionBuilder> predicateFunction(
-            FunctionName functionName,
-            BiFunction<Integer, Integer, Boolean> integerFunc,
-            BiFunction<Long, Long, Boolean> longFunc,
-            BiFunction<Float, Float, Boolean> floatFunc,
-            BiFunction<Double, Double, Boolean> doubleFunc,
-            BiFunction<String, String, Boolean> stringFunc,
-            BiFunction<Boolean, Boolean, Boolean> booleanFunc,
-            BiFunction<List, List, Boolean> listFunc,
-            BiFunction<Map, Map, Boolean> mapFunc) {
-        ImmutableMap.Builder<FunctionSignature, FunctionBuilder> builder = new ImmutableMap.Builder<>();
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.INTEGER, ExprType.INTEGER)),
-                equal(functionName, integerFunc, ExprValueUtils::getIntegerValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.LONG, ExprType.LONG)),
-                equal(functionName, longFunc, ExprValueUtils::getLongValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.FLOAT, ExprType.FLOAT)),
-                equal(functionName, floatFunc, ExprValueUtils::getFloatValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.DOUBLE, ExprType.DOUBLE)),
-                equal(functionName, doubleFunc, ExprValueUtils::getDoubleValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.STRING, ExprType.STRING)),
-                equal(functionName, stringFunc, ExprValueUtils::getStringValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)),
-                equal(functionName, booleanFunc, ExprValueUtils::getBooleanValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.ARRAY, ExprType.ARRAY)),
-                equal(functionName, listFunc, ExprValueUtils::getCollectionValue,
-                        ExprType.BOOLEAN));
-        builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.STRUCT, ExprType.STRUCT)),
-                equal(functionName, mapFunc, ExprValueUtils::getTupleValue,
-                        ExprType.BOOLEAN));
-        return builder.build();
-    }
+  private static Map<FunctionSignature, FunctionBuilder> predicateFunction(
+      FunctionName functionName,
+      BiFunction<Integer, Integer, Boolean> integerFunc,
+      BiFunction<Long, Long, Boolean> longFunc,
+      BiFunction<Float, Float, Boolean> floatFunc,
+      BiFunction<Double, Double, Boolean> doubleFunc,
+      BiFunction<String, String, Boolean> stringFunc,
+      BiFunction<Boolean, Boolean, Boolean> booleanFunc,
+      BiFunction<List, List, Boolean> listFunc,
+      BiFunction<Map, Map, Boolean> mapFunc) {
+    ImmutableMap.Builder<FunctionSignature, FunctionBuilder> builder = new ImmutableMap.Builder<>();
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.INTEGER, ExprType.INTEGER)),
+            equalTo(functionName, integerFunc, ExprValueUtils::getIntegerValue,
+                ExprType.BOOLEAN));
+    builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.LONG, ExprType.LONG)),
+        equalTo(functionName, longFunc, ExprValueUtils::getLongValue,
+            ExprType.BOOLEAN));
+    builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.FLOAT, ExprType.FLOAT)),
+        equalTo(functionName, floatFunc, ExprValueUtils::getFloatValue,
+            ExprType.BOOLEAN));
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.DOUBLE, ExprType.DOUBLE)),
+            equalTo(functionName, doubleFunc, ExprValueUtils::getDoubleValue,
+                ExprType.BOOLEAN));
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.STRING, ExprType.STRING)),
+            equalTo(functionName, stringFunc, ExprValueUtils::getStringValue,
+                ExprType.BOOLEAN));
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.BOOLEAN, ExprType.BOOLEAN)),
+            equalTo(functionName, booleanFunc, ExprValueUtils::getBooleanValue,
+                ExprType.BOOLEAN));
+    builder.put(new FunctionSignature(functionName, Arrays.asList(ExprType.ARRAY, ExprType.ARRAY)),
+        equalTo(functionName, listFunc, ExprValueUtils::getCollectionValue,
+            ExprType.BOOLEAN));
+    builder
+        .put(new FunctionSignature(functionName, Arrays.asList(ExprType.STRUCT, ExprType.STRUCT)),
+            equalTo(functionName, mapFunc, ExprValueUtils::getTupleValue,
+                ExprType.BOOLEAN));
+    return builder.build();
+  }
 
-    private static FunctionBuilder binaryPredicate(FunctionName functionName,
-                                                   Table<ExprValue, ExprValue, ExprValue> logicalTable,
-                                                   ExprType returnType) {
-        return arguments -> new FunctionExpression(functionName, arguments) {
-            @Override
-            public ExprValue valueOf(Environment<Expression, ExprValue> env) {
-                ExprValue arg1 = arguments.get(0).valueOf(env);
-                ExprValue arg2 = arguments.get(1).valueOf(env);
-                if (logicalTable.contains(arg1, arg2)) {
-                    return logicalTable.get(arg1, arg2);
-                } else {
-                    return logicalTable.get(arg2, arg1);
-                }
-            }
+  private static FunctionBuilder binaryPredicate(FunctionName functionName,
+                                                 Table<ExprValue, ExprValue, ExprValue> table,
+                                                 ExprType returnType) {
+    return arguments -> new FunctionExpression(functionName, arguments) {
+      @Override
+      public ExprValue valueOf(Environment<Expression, ExprValue> env) {
+        ExprValue arg1 = arguments.get(0).valueOf(env);
+        ExprValue arg2 = arguments.get(1).valueOf(env);
+        if (table.contains(arg1, arg2)) {
+          return table.get(arg1, arg2);
+        } else {
+          return table.get(arg2, arg1);
+        }
+      }
 
-            @Override
-            public ExprType type(Environment<Expression, ExprType> env) {
-                return returnType;
-            }
-        };
-    }
+      @Override
+      public ExprType type(Environment<Expression, ExprType> env) {
+        return returnType;
+      }
+    };
+  }
 
-    private static <T, R> FunctionBuilder equal(FunctionName functionName,
+  private static <T, R> FunctionBuilder equalTo(FunctionName functionName,
                                                 BiFunction<T, T, R> function,
                                                 Function<ExprValue, T> observer,
                                                 ExprType returnType) {
-        return arguments -> new FunctionExpression(functionName, arguments) {
-            @Override
-            public ExprValue valueOf(Environment<Expression, ExprValue> env) {
-                ExprValue arg1 = arguments.get(0).valueOf(env);
-                ExprValue arg2 = arguments.get(1).valueOf(env);
-                if (equalTable.contains(arg1, arg2)) {
-                    return equalTable.get(arg1, arg2);
-                } else if (arg1.isMissing() || arg1.isNull() || arg2.isMissing() || arg2.isNull()) {
-                    return LITERAL_FALSE;
-                } else {
-                    return ExprValueUtils.fromObjectValue(
-                            function.apply(observer.apply(arg1), observer.apply(arg2)));
-                }
-            }
+    return arguments -> new FunctionExpression(functionName, arguments) {
+      @Override
+      public ExprValue valueOf(Environment<Expression, ExprValue> env) {
+        ExprValue arg1 = arguments.get(0).valueOf(env);
+        ExprValue arg2 = arguments.get(1).valueOf(env);
+        if (equalTable.contains(arg1, arg2)) {
+          return equalTable.get(arg1, arg2);
+        } else if (arg1.isMissing() || arg1.isNull() || arg2.isMissing() || arg2.isNull()) {
+          return LITERAL_FALSE;
+        } else {
+          return ExprValueUtils.fromObjectValue(
+              function.apply(observer.apply(arg1), observer.apply(arg2)));
+        }
+      }
 
-            @Override
-            public ExprType type(Environment<Expression, ExprType> env) {
-                return returnType;
-            }
-        };
-    }
+      @Override
+      public ExprType type(Environment<Expression, ExprType> env) {
+        return returnType;
+      }
+    };
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunction.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunction.java
index d70f92b29f..953fb6b025 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunction.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunction.java
@@ -15,6 +15,11 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate;
 
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_FALSE;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
@@ -27,15 +32,9 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionResolver;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature;
 import com.google.common.collect.ImmutableMap;
-import lombok.experimental.UtilityClass;
-
 import java.util.Arrays;
 import java.util.Map;
-
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_FALSE;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
+import lombok.experimental.UtilityClass;
 
 /**
  * The definition of unary predicate function
@@ -43,50 +42,50 @@
  */
 @UtilityClass
 public class UnaryPredicateFunction {
-    public static void register(BuiltinFunctionRepository repository) {
-        repository.register(not());
-    }
+  public static void register(BuiltinFunctionRepository repository) {
+    repository.register(not());
+  }
 
-    /**
-     * The or logic
-     * A       NOT A
-     * TRUE    FALSE
-     * FALSE   TRUE
-     * NULL    NULL
-     * MISSING MISSING
-     */
-    private static Map<ExprValue, ExprValue> notMap =
-            new ImmutableMap.Builder<ExprValue, ExprValue>()
-                    .put(LITERAL_TRUE, LITERAL_FALSE)
-                    .put(LITERAL_FALSE, LITERAL_TRUE)
-                    .put(LITERAL_NULL, LITERAL_NULL)
-                    .put(LITERAL_MISSING, LITERAL_MISSING)
-                    .build();
+  /**
+   * The or logic.
+   * A       NOT A
+   * TRUE    FALSE
+   * FALSE   TRUE
+   * NULL    NULL
+   * MISSING MISSING
+   */
+  private static Map<ExprValue, ExprValue> notMap =
+      new ImmutableMap.Builder<ExprValue, ExprValue>()
+          .put(LITERAL_TRUE, LITERAL_FALSE)
+          .put(LITERAL_FALSE, LITERAL_TRUE)
+          .put(LITERAL_NULL, LITERAL_NULL)
+          .put(LITERAL_MISSING, LITERAL_MISSING)
+          .build();
 
-    private static FunctionResolver not() {
-        FunctionName functionName = BuiltinFunctionName.NOT.getName();
-        return FunctionResolver.builder()
-                .functionName(functionName)
-                .functionBundle(new FunctionSignature(functionName,
-                        Arrays.asList(ExprType.BOOLEAN)), predicateFunction(functionName,
-                        notMap, ExprType.BOOLEAN))
-                .build();
-    }
+  private static FunctionResolver not() {
+    FunctionName functionName = BuiltinFunctionName.NOT.getName();
+    return FunctionResolver.builder()
+        .functionName(functionName)
+        .functionBundle(new FunctionSignature(functionName,
+            Arrays.asList(ExprType.BOOLEAN)), predicateFunction(functionName,
+            notMap, ExprType.BOOLEAN))
+        .build();
+  }
 
-    private static FunctionBuilder predicateFunction(
-            FunctionName functionName,
-            Map<ExprValue, ExprValue> map,
-            ExprType returnType) {
-        return arguments -> new FunctionExpression(functionName, arguments) {
-            @Override
-            public ExprValue valueOf(Environment<Expression, ExprValue> env) {
-                return map.get(arguments.get(0).valueOf(env));
-            }
+  private static FunctionBuilder predicateFunction(
+      FunctionName functionName,
+      Map<ExprValue, ExprValue> map,
+      ExprType returnType) {
+    return arguments -> new FunctionExpression(functionName, arguments) {
+      @Override
+      public ExprValue valueOf(Environment<Expression, ExprValue> env) {
+        return map.get(arguments.get(0).valueOf(env));
+      }
 
-            @Override
-            public ExprType type(Environment<Expression, ExprType> env) {
-                return returnType;
-            }
-        };
-    }
+      @Override
+      public ExprType type(Environment<Expression, ExprType> env) {
+        return returnType;
+      }
+    };
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/PlanNode.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/PlanNode.java
index 2af2f381d8..49bac8cf46 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/PlanNode.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/PlanNode.java
@@ -18,14 +18,14 @@
 import java.util.List;
 
 /**
- * The definition of Plan Node
+ * The definition of Plan Node.
  */
 public interface PlanNode<T extends PlanNode> {
 
-    /**
-     * Return the child nodes.
-     *
-     * @return child nodes.
-     */
-    List<T> getChild();
+  /**
+   * Return the child nodes.
+   *
+   * @return child nodes.
+   */
+  List<T> getChild();
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/Planner.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/Planner.java
index 9815c74f29..fb96e02444 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/Planner.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/Planner.java
@@ -30,39 +30,39 @@
 @RequiredArgsConstructor
 public class Planner {
 
-    /**
-     * Storage engine
-     */
-    private final StorageEngine storageEngine;
+  /**
+   * Storage engine.
+   */
+  private final StorageEngine storageEngine;
 
-    /**
-     * Generate optimal physical plan for logical plan.
-     * TODO: for now just delegate entire logical plan to storage engine.
-     *
-     * @param plan  logical plan
-     * @return      optimal physical plan
-     */
-    public PhysicalPlan plan(LogicalPlan plan) {
-        String tableName = findTableName(plan);
-        Table table = storageEngine.getTable(tableName);
-        return table.implement(plan);
-    }
+  /**
+   * Generate optimal physical plan for logical plan.
+   * TODO: for now just delegate entire logical plan to storage engine.
+   *
+   * @param plan logical plan
+   * @return optimal physical plan
+   */
+  public PhysicalPlan plan(LogicalPlan plan) {
+    String tableName = findTableName(plan);
+    Table table = storageEngine.getTable(tableName);
+    return table.implement(plan);
+  }
 
-    private String findTableName(LogicalPlan plan) {
-        return plan.accept(new LogicalPlanNodeVisitor<String, Object>() {
+  private String findTableName(LogicalPlan plan) {
+    return plan.accept(new LogicalPlanNodeVisitor<String, Object>() {
 
-            @Override
-            protected String visitNode(LogicalPlan node, Object context) {
-                // So far all logical node has single child except LogicalRelation
-                //  whose visitRelation() is already overridden.
-                return node.getChild().get(0).accept(this, context);
-            }
+      @Override
+      protected String visitNode(LogicalPlan node, Object context) {
+        // So far all logical node has single child except LogicalRelation
+        //  whose visitRelation() is already overridden.
+        return node.getChild().get(0).accept(this, context);
+      }
 
-            @Override
-            public String visitRelation(LogicalRelation node, Object context) {
-                return node.getRelationName();
-            }
-        }, null);
-    }
+      @Override
+      public String visitRelation(LogicalRelation node, Object context) {
+        return node.getRelationName();
+      }
+    }, null);
+  }
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalAggregation.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalAggregation.java
index 0e6c10cd71..ef89d91cef 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalAggregation.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalAggregation.java
@@ -17,14 +17,13 @@
 
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.expression.aggregation.Aggregator;
+import java.util.Collections;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-import java.util.Collections;
-import java.util.List;
-
 /**
  * Logical Aggregation.
  */
@@ -32,19 +31,19 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LogicalAggregation extends LogicalPlan {
-    private final LogicalPlan child;
-    @Getter
-    private final List<Aggregator> aggregatorList;
-    @Getter
-    private final List<Expression> groupByList;
+  private final LogicalPlan child;
+  @Getter
+  private final List<Aggregator> aggregatorList;
+  @Getter
+  private final List<Expression> groupByList;
 
-    @Override
-    public List<LogicalPlan> getChild() {
-        return Collections.singletonList(child);
-    }
+  @Override
+  public List<LogicalPlan> getChild() {
+    return Collections.singletonList(child);
+  }
 
-    @Override
-    public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitAggregation(this, context);
-    }
+  @Override
+  public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitAggregation(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalDedupe.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalDedupe.java
index f410e56d46..5276c7a0b6 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalDedupe.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalDedupe.java
@@ -24,7 +24,7 @@
 import lombok.ToString;
 
 /**
- * Logical Dedupe Plan
+ * Logical Dedupe Plan.
  */
 @Getter
 @ToString
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEval.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEval.java
index 8582a779ef..5e3f117610 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEval.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEval.java
@@ -35,7 +35,8 @@
 @RequiredArgsConstructor
 public class LogicalEval extends LogicalPlan {
   private final LogicalPlan child;
-  @Getter private final List<Pair<ReferenceExpression, Expression>> expressions;
+  @Getter
+  private final List<Pair<ReferenceExpression, Expression>> expressions;
 
   @Override
   public List<LogicalPlan> getChild() {
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalFilter.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalFilter.java
index 20d2a8476f..306104ca6f 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalFilter.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalFilter.java
@@ -16,14 +16,13 @@
 package com.amazon.opendistroforelasticsearch.sql.planner.logical;
 
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
+import java.util.Arrays;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-import java.util.Arrays;
-import java.util.List;
-
 /**
  * Logical Filter represent the filter relation.
  */
@@ -31,17 +30,17 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LogicalFilter extends LogicalPlan {
-    private final LogicalPlan child;
-    @Getter
-    private final Expression condition;
+  private final LogicalPlan child;
+  @Getter
+  private final Expression condition;
 
-    @Override
-    public List<LogicalPlan> getChild() {
-        return Arrays.asList(child);
-    }
+  @Override
+  public List<LogicalPlan> getChild() {
+    return Arrays.asList(child);
+  }
 
-    @Override
-    public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitFilter(this, context);
-    }
+  @Override
+  public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitFilter(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlan.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlan.java
index 5f1d60bed0..035598d568 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlan.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlan.java
@@ -21,14 +21,14 @@
  * The abstract base class for all the Logical Plan node.
  */
 public abstract class LogicalPlan implements PlanNode<LogicalPlan> {
-    /**
-     * Accept the {@link LogicalPlanNodeVisitor}.
-     *
-     * @param visitor visitor.
-     * @param context visitor context.
-     * @param <R>     returned object type.
-     * @param <C>     context type.
-     * @return returned object.
-     */
-    public abstract <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context);
+  /**
+   * Accept the {@link LogicalPlanNodeVisitor}.
+   *
+   * @param visitor visitor.
+   * @param context visitor context.
+   * @param <R>     returned object type.
+   * @param <C>     context type.
+   * @return returned object.
+   */
+  public abstract <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context);
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanDSL.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanDSL.java
index fb1cbb69f4..98df7dacf3 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanDSL.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanDSL.java
@@ -21,13 +21,14 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.aggregation.Aggregator;
 import com.google.common.collect.ImmutableSet;
 import java.util.Arrays;
-import lombok.experimental.UtilityClass;
-
 import java.util.List;
 import java.util.Map;
+import lombok.experimental.UtilityClass;
 import org.apache.commons.lang3.tuple.Pair;
 
-/** Logical Plan DSL. */
+/**
+ * Logical Plan DSL.
+ */
 @UtilityClass
 public class LogicalPlanDSL {
   public static LogicalPlan aggregation(
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalProject.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalProject.java
index a8ab31523b..a24e5be68a 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalProject.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalProject.java
@@ -30,17 +30,17 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LogicalProject extends LogicalPlan {
-    private final LogicalPlan child;
-    @Getter
-    private final List<ReferenceExpression> projectList;
+  private final LogicalPlan child;
+  @Getter
+  private final List<ReferenceExpression> projectList;
 
-    @Override
-    public List<LogicalPlan> getChild() {
-        return Arrays.asList(child);
-    }
+  @Override
+  public List<LogicalPlan> getChild() {
+    return Arrays.asList(child);
+  }
 
-    @Override
-    public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitProject(this, context);
-    }
+  @Override
+  public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitProject(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelation.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelation.java
index 61dd8f95f5..a836ce043b 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelation.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelation.java
@@ -16,13 +16,12 @@
 package com.amazon.opendistroforelasticsearch.sql.planner.logical;
 
 import com.google.common.collect.ImmutableList;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-import java.util.List;
-
 /**
  * Logical Relation represent the data source.
  */
@@ -30,16 +29,16 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LogicalRelation extends LogicalPlan {
-    @Getter
-    private final String relationName;
+  @Getter
+  private final String relationName;
 
-    @Override
-    public List<LogicalPlan> getChild() {
-        return ImmutableList.of();
-    }
+  @Override
+  public List<LogicalPlan> getChild() {
+    return ImmutableList.of();
+  }
 
-    @Override
-    public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitRelation(this, context);
-    }
+  @Override
+  public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitRelation(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRemove.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRemove.java
index 4b73048c64..11d280cd9b 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRemove.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRemove.java
@@ -31,17 +31,17 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LogicalRemove extends LogicalPlan {
-    private final LogicalPlan child;
-    @Getter
-    private final Set<ReferenceExpression> removeList;
+  private final LogicalPlan child;
+  @Getter
+  private final Set<ReferenceExpression> removeList;
 
-    @Override
-    public List<LogicalPlan> getChild() {
-        return Arrays.asList(child);
-    }
+  @Override
+  public List<LogicalPlan> getChild() {
+    return Arrays.asList(child);
+  }
 
-    @Override
-    public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitRemove(this, context);
-    }
+  @Override
+  public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitRemove(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRename.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRename.java
index 14a8a26ba5..812ac329e1 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRename.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRename.java
@@ -32,17 +32,17 @@
 @EqualsAndHashCode
 @RequiredArgsConstructor
 public class LogicalRename extends LogicalPlan {
-    private final LogicalPlan child;
-    @Getter
-    private final Map<ReferenceExpression, ReferenceExpression> renameMap;
+  private final LogicalPlan child;
+  @Getter
+  private final Map<ReferenceExpression, ReferenceExpression> renameMap;
 
-    @Override
-    public List<LogicalPlan> getChild() {
-        return Collections.singletonList(child);
-    }
+  @Override
+  public List<LogicalPlan> getChild() {
+    return Collections.singletonList(child);
+  }
 
-    @Override
-    public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitRename(this, context);
-    }
+  @Override
+  public <R, C> R accept(LogicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitRename(this, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperator.java
index 68d19e13b5..6e58ad07e6 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperator.java
@@ -37,128 +37,138 @@
 import lombok.ToString;
 
 /**
- * Group the all the input {@link BindingTuple} by {@link AggregationOperator#groupByExprList}, calculate the
- * aggregation result by using {@link AggregationOperator#aggregatorList}
+ * Group the all the input {@link BindingTuple} by {@link AggregationOperator#groupByExprList},
+ * calculate the aggregation result by using {@link AggregationOperator#aggregatorList}.
  */
 @EqualsAndHashCode
 @ToString
 public class AggregationOperator extends PhysicalPlan {
 
-    private final PhysicalPlan input;
-    private final List<Aggregator> aggregatorList;
-    private final List<Expression> groupByExprList;
-    @EqualsAndHashCode.Exclude
-    private final Group group;
-    @EqualsAndHashCode.Exclude
-    private Iterator<ExprValue> iterator;
-
-    public AggregationOperator(PhysicalPlan input, List<Aggregator> aggregatorList,
-            List<Expression> groupByExprList) {
-        this.input = input;
-        this.aggregatorList = aggregatorList;
-        this.groupByExprList = groupByExprList;
-        this.group = new Group();
+  private final PhysicalPlan input;
+  private final List<Aggregator> aggregatorList;
+  private final List<Expression> groupByExprList;
+  @EqualsAndHashCode.Exclude
+  private final Group group;
+  @EqualsAndHashCode.Exclude
+  private Iterator<ExprValue> iterator;
+
+  /**
+   * AggregationOperator Constructor.
+   * @param input Input {@link PhysicalPlan}
+   * @param aggregatorList List of {@link Aggregator}
+   * @param groupByExprList List of group by {@link Expression}
+   */
+  public AggregationOperator(PhysicalPlan input, List<Aggregator> aggregatorList,
+                             List<Expression> groupByExprList) {
+    this.input = input;
+    this.aggregatorList = aggregatorList;
+    this.groupByExprList = groupByExprList;
+    this.group = new Group();
+  }
+
+  @Override
+  public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitAggregation(this, context);
+  }
+
+  @Override
+  public List<PhysicalPlan> getChild() {
+    return Collections.singletonList(input);
+  }
+
+
+  @Override
+  public boolean hasNext() {
+    return iterator.hasNext();
+  }
+
+  @Override
+  public ExprValue next() {
+    return iterator.next();
+  }
+
+  @Override
+  public void open() {
+    super.open();
+    while (input.hasNext()) {
+      group.push(input.next());
     }
+    iterator = group.result().iterator();
+  }
 
-    @Override
-    public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitAggregation(this, context);
-    }
-
-    @Override
-    public List<PhysicalPlan> getChild() {
-        return Collections.singletonList(input);
-    }
+  @VisibleForTesting
+  @RequiredArgsConstructor
+  public class Group {
 
+    private final Map<GroupKey, List<Map.Entry<Aggregator, AggregationState>>> groupListMap =
+        new HashMap<>();
 
-    @Override
-    public boolean hasNext() {
-        return iterator.hasNext();
-    }
-
-    @Override
-    public ExprValue next() {
-        return iterator.next();
+    /**
+     * Push the BindingTuple to Group. Two functions will be applied to each BindingTuple to
+     * generate the {@link GroupKey} and {@link AggregationState}
+     * Key = GroupKey(bindingTuple), State = Aggregator(bindingTuple)
+     */
+    public void push(ExprValue inputValue) {
+      GroupKey groupKey = new GroupKey(inputValue);
+      groupListMap.computeIfAbsent(groupKey, k ->
+          aggregatorList.stream()
+              .map(aggregator -> new AbstractMap.SimpleEntry<>(aggregator,
+                  aggregator.create()))
+              .collect(Collectors.toList())
+      );
+      groupListMap.computeIfPresent(groupKey, (key, aggregatorList) -> {
+        aggregatorList
+            .forEach(entry -> entry.getKey().iterate(inputValue.bindingTuples(), entry.getValue()));
+        return aggregatorList;
+      });
     }
 
-    @Override
-    public void open() {
-        super.open();
-        while (input.hasNext()) {
-            group.push(input.next());
+    /**
+     * Get the list of {@link BindingTuple} for each group.
+     */
+    public List<ExprValue> result() {
+      ImmutableList.Builder<ExprValue> resultBuilder = new ImmutableList.Builder<>();
+      for (Map.Entry<GroupKey, List<Map.Entry<Aggregator, AggregationState>>> entry : groupListMap
+          .entrySet()) {
+        LinkedHashMap<String, ExprValue> map = new LinkedHashMap<>();
+        map.putAll(entry.getKey().groupKeyMap());
+        for (Map.Entry<Aggregator, AggregationState> stateEntry : entry.getValue()) {
+          map.put(stateEntry.getKey().toString(), stateEntry.getValue().result());
         }
-        iterator = group.result().iterator();
+        resultBuilder.add(ExprTupleValue.fromExprValueMap(map));
+      }
+      return resultBuilder.build();
     }
+  }
 
-    @VisibleForTesting
-    @RequiredArgsConstructor
-    public class Group {
-
-        private final Map<GroupKey, List<Map.Entry<Aggregator, AggregationState>>> groupListMap = new HashMap<>();
-
-        /**
-         * Push the BindingTuple to Group. Two functions will be applied to each BindingTuple to generate the
-         * {@link GroupKey} and {@link AggregationState}
-         * Key = GroupKey(bindingTuple), State = Aggregator(bindingTuple)
-         */
-        public void push(ExprValue inputValue) {
-            GroupKey groupKey = new GroupKey(inputValue);
-            groupListMap.computeIfAbsent(groupKey, k ->
-                    aggregatorList.stream()
-                            .map(aggregator -> new AbstractMap.SimpleEntry<>(aggregator,
-                                    aggregator.create()))
-                            .collect(Collectors.toList())
-            );
-            groupListMap.computeIfPresent(groupKey, (key, aggregatorList) -> {
-                aggregatorList
-                        .forEach(entry -> entry.getKey().iterate(inputValue.bindingTuples(), entry.getValue()));
-                return aggregatorList;
-            });
-        }
+  /**
+   * Group Key.
+   */
+  @EqualsAndHashCode
+  @VisibleForTesting
+  public class GroupKey {
 
-        /**
-         * Get the list of {@link BindingTuple} for each group.
-         */
-        public List<ExprValue> result() {
-            ImmutableList.Builder<ExprValue> resultBuilder = new ImmutableList.Builder<>();
-            for (Map.Entry<GroupKey, List<Map.Entry<Aggregator, AggregationState>>> entry : groupListMap
-                    .entrySet()) {
-                LinkedHashMap<String, ExprValue> map = new LinkedHashMap<>();
-                map.putAll(entry.getKey().groupKeyMap());
-                for (Map.Entry<Aggregator, AggregationState> stateEntry : entry.getValue()) {
-                    map.put(stateEntry.getKey().toString(), stateEntry.getValue().result());
-                }
-                resultBuilder.add(ExprTupleValue.fromExprValueMap(map));
-            }
-            return resultBuilder.build();
-        }
-    }
+    private final List<ExprValue> groupByValueList;
 
     /**
-     * Group Key.
+     * GroupKey constructor.
      */
-    @EqualsAndHashCode
-    @VisibleForTesting
-    public class GroupKey {
-
-        private final List<ExprValue> groupByValueList;
-
-        public GroupKey(ExprValue value) {
-            this.groupByValueList = new ArrayList<>();
-            for (Expression groupExpr : groupByExprList) {
-                this.groupByValueList.add(groupExpr.valueOf(value.bindingTuples()));
-            }
-        }
+    public GroupKey(ExprValue value) {
+      this.groupByValueList = new ArrayList<>();
+      for (Expression groupExpr : groupByExprList) {
+        this.groupByValueList.add(groupExpr.valueOf(value.bindingTuples()));
+      }
+    }
 
-        /**
-         * Return the Map of group field and group field value.
-         */
-        public LinkedHashMap<String, ExprValue> groupKeyMap() {
-            LinkedHashMap<String, ExprValue> map = new LinkedHashMap<>();
-            for (int i = 0; i < groupByExprList.size(); i++) {
-                map.put(groupByExprList.get(i).toString(), groupByValueList.get(i));
-            }
-            return map;
-        }
+    /**
+     * Return the Map of group field and group field value.
+     */
+    public LinkedHashMap<String, ExprValue> groupKeyMap() {
+      LinkedHashMap<String, ExprValue> map = new LinkedHashMap<>();
+      for (int i = 0; i < groupByExprList.size(); i++) {
+        map.put(groupByExprList.get(i).toString(), groupByValueList.get(i));
+      }
+      return map;
     }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperator.java
index bdd22d186a..c29d6a2ab6 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperator.java
@@ -41,8 +41,10 @@ public class DedupeOperator extends PhysicalPlan {
   private final Boolean keepEmpty;
   private final Boolean consecutive;
 
-  @EqualsAndHashCode.Exclude private final Deduper<List<ExprValue>> deduper;
-  @EqualsAndHashCode.Exclude private ExprValue next;
+  @EqualsAndHashCode.Exclude
+  private final Deduper<List<ExprValue>> deduper;
+  @EqualsAndHashCode.Exclude
+  private ExprValue next;
 
   private static final Integer ALL_ONE_DUPLICATION = 1;
   private static final Boolean IGNORE_EMPTY = false;
@@ -55,6 +57,14 @@ public DedupeOperator(PhysicalPlan input, List<Expression> dedupeList) {
     this(input, dedupeList, ALL_ONE_DUPLICATION, IGNORE_EMPTY, NON_CONSECUTIVE);
   }
 
+  /**
+   * Dedup Constructor.
+   * @param input input {@link PhysicalPlan}
+   * @param dedupeList list of dedupe {@link Expression}
+   * @param allowedDuplication max allowed duplication
+   * @param keepEmpty keep empty
+   * @param consecutive consecutive mode
+   */
   @NonNull
   public DedupeOperator(
       PhysicalPlan input,
@@ -103,7 +113,7 @@ public ExprValue next() {
    * <p>If any value evaluted by {@link DedupeOperator#dedupeList} is NULL or MISSING, then the *
    * return value is decided by keepEmpty option, default value is ignore.
    *
-   * @param value
+   * @param value {@link ExprValue}.
    * @return true: keep, false: ignore
    */
   public boolean keep(ExprValue value) {
@@ -132,7 +142,9 @@ static class Deduper<K> {
     private final BiFunction<Map<K, Integer>, K, Integer> seenFirstTime;
     private final Map<K, Integer> seenMap = new ConcurrentHashMap<>();
 
-    /** The Historical Deduper monitor the duplicated element with all the seen value. */
+    /**
+     * The Historical Deduper monitor the duplicated element with all the seen value.
+     */
     public static <K> Deduper<K> historicalDeduper() {
       return new Deduper<>(
           (map, key) -> {
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperator.java
index dc8c067414..340bddd4ef 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperator.java
@@ -90,7 +90,11 @@ public ExprValue next() {
     }
   }
 
-  /** Construct Map<String, ExprValue> from {@link EvalOperator#expressionList} */
+  /**
+   * Evaluate the expression in the {@link EvalOperator#expressionList} with {@link Environment}.
+   * @param env {@link Environment}
+   * @return The mapping of reference and {@link ExprValue} for each expression.
+   */
   private Map<String, ExprValue> eval(Environment<Expression, ExprValue> env) {
     Map<String, ExprValue> evalResultMap = new LinkedHashMap<>();
     for (Pair<ReferenceExpression, Expression> pair : expressionList) {
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperator.java
index 0c24808074..0a20bad304 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperator.java
@@ -5,13 +5,12 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate.BinaryPredicateFunction;
 import com.amazon.opendistroforelasticsearch.sql.storage.bindingtuple.BindingTuple;
+import java.util.Collections;
+import java.util.List;
 import lombok.EqualsAndHashCode;
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-import java.util.Collections;
-import java.util.List;
-
 /**
  * The Filter operator use the conditions to evaluate the input {@link BindingTuple}.
  * The Filter operator only return the results that evaluated to true.
@@ -21,35 +20,35 @@
 @ToString
 @RequiredArgsConstructor
 public class FilterOperator extends PhysicalPlan {
-    private final PhysicalPlan input;
-    private final Expression conditions;
-    private ExprValue next = null;
+  private final PhysicalPlan input;
+  private final Expression conditions;
+  private ExprValue next = null;
 
-    @Override
-    public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitFilter(this, context);
-    }
+  @Override
+  public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitFilter(this, context);
+  }
 
-    @Override
-    public List<PhysicalPlan> getChild() {
-        return Collections.singletonList(input);
-    }
+  @Override
+  public List<PhysicalPlan> getChild() {
+    return Collections.singletonList(input);
+  }
 
-    @Override
-    public boolean hasNext() {
-        while (input.hasNext()) {
-            ExprValue inputValue = input.next();
-            ExprValue exprValue = conditions.valueOf(inputValue.bindingTuples());
-            if (ExprValueUtils.getBooleanValue(exprValue)) {
-                next = inputValue;
-                return true;
-            }
-        }
-        return false;
+  @Override
+  public boolean hasNext() {
+    while (input.hasNext()) {
+      ExprValue inputValue = input.next();
+      ExprValue exprValue = conditions.valueOf(inputValue.bindingTuples());
+      if (ExprValueUtils.getBooleanValue(exprValue)) {
+        next = inputValue;
+        return true;
+      }
     }
+    return false;
+  }
 
-    @Override
-    public ExprValue next() {
-        return next;
-    }
+  @Override
+  public ExprValue next() {
+    return next;
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlan.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlan.java
index 3fa9e09fcc..e7f64c84ec 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlan.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlan.java
@@ -20,27 +20,27 @@
 import java.util.Iterator;
 
 /**
- * Physical plan
+ * Physical plan.
  */
 public abstract class PhysicalPlan implements PlanNode<PhysicalPlan>,
-        Iterator<ExprValue>,
-        AutoCloseable {
-    /**
-     * Accept the {@link PhysicalPlanNodeVisitor}.
-     *
-     * @param visitor visitor.
-     * @param context visitor context.
-     * @param <R>     returned object type.
-     * @param <C>     context type.
-     * @return returned object.
-     */
-    public abstract <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context);
+    Iterator<ExprValue>,
+    AutoCloseable {
+  /**
+   * Accept the {@link PhysicalPlanNodeVisitor}.
+   *
+   * @param visitor visitor.
+   * @param context visitor context.
+   * @param <R>     returned object type.
+   * @param <C>     context type.
+   * @return returned object.
+   */
+  public abstract <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context);
 
-    public void open() {
-        getChild().forEach(PhysicalPlan::open);
-    }
+  public void open() {
+    getChild().forEach(PhysicalPlan::open);
+  }
 
-    public void close() {
-        getChild().forEach(PhysicalPlan::close);
-    }
+  public void close() {
+    getChild().forEach(PhysicalPlan::close);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanDSL.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanDSL.java
index e91dd29ceb..620a18d3a6 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanDSL.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanDSL.java
@@ -26,7 +26,9 @@
 import lombok.experimental.UtilityClass;
 import org.apache.commons.lang3.tuple.Pair;
 
-/** Physical Plan DSL. */
+/**
+ * Physical Plan DSL.
+ */
 @UtilityClass
 public class PhysicalPlanDSL {
 
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitor.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitor.java
index b676e15a15..7975aa07bf 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitor.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitor.java
@@ -25,39 +25,39 @@
  */
 public abstract class PhysicalPlanNodeVisitor<R, C> {
 
-    protected R visitNode(PhysicalPlan node, C context) {
-        return null;
-    }
+  protected R visitNode(PhysicalPlan node, C context) {
+    return null;
+  }
 
-    public R visitFilter(FilterOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitFilter(FilterOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitAggregation(AggregationOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitAggregation(AggregationOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitRename(RenameOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitRename(RenameOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitTableScan(TableScanOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitTableScan(TableScanOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitProject(ProjectOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitProject(ProjectOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitRemove(RemoveOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitRemove(RemoveOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitEval(EvalOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitEval(EvalOperator node, C context) {
+    return visitNode(node, context);
+  }
 
-    public R visitDedupe(DedupeOperator node, C context) {
-        return visitNode(node, context);
-    }
+  public R visitDedupe(DedupeOperator node, C context) {
+    return visitNode(node, context);
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperator.java
index 30928bd1ab..019c7a7f0b 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperator.java
@@ -26,7 +26,9 @@
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-/** Project the fields specified in {@link ProjectOperator#projectList} from input. */
+/**
+ * Project the fields specified in {@link ProjectOperator#projectList} from input.
+ */
 @ToString
 @EqualsAndHashCode
 @RequiredArgsConstructor
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperator.java
index 20f151c35e..810469de72 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperator.java
@@ -33,7 +33,9 @@
 import lombok.RequiredArgsConstructor;
 import lombok.ToString;
 
-/** Remove the fields specified in {@link RemoveOperator#removeList} from input. */
+/**
+ * Remove the fields specified in {@link RemoveOperator#removeList} from input.
+ */
 @ToString
 @EqualsAndHashCode
 @RequiredArgsConstructor
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperator.java
index 8fb029e0c2..bbf3cc69ab 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperator.java
@@ -41,40 +41,40 @@
 @ToString
 @RequiredArgsConstructor
 public class RenameOperator extends PhysicalPlan {
-    private final PhysicalPlan input;
-    private final Map<ReferenceExpression, ReferenceExpression> mapping;
+  private final PhysicalPlan input;
+  private final Map<ReferenceExpression, ReferenceExpression> mapping;
 
-    @Override
-    public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitRename(this, context);
-    }
+  @Override
+  public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitRename(this, context);
+  }
 
-    @Override
-    public List<PhysicalPlan> getChild() {
-        return Collections.singletonList(input);
-    }
+  @Override
+  public List<PhysicalPlan> getChild() {
+    return Collections.singletonList(input);
+  }
 
-    @Override
-    public boolean hasNext() {
-        return input.hasNext();
-    }
+  @Override
+  public boolean hasNext() {
+    return input.hasNext();
+  }
 
-    @Override
-    public ExprValue next() {
-        ExprValue inputValue = input.next();
-        if (STRUCT == inputValue.type()) {
-            Map<String, ExprValue> tupleValue = ExprValueUtils.getTupleValue(inputValue);
-            ImmutableMap.Builder<String, ExprValue> mapBuilder = new Builder<>();
-            for (String bindName : tupleValue.keySet()) {
-                if (mapping.containsKey(DSL.ref(bindName))) {
-                    mapBuilder.put(mapping.get(DSL.ref(bindName)).getAttr(), tupleValue.get(bindName));
-                } else {
-                    mapBuilder.put(bindName, tupleValue.get(bindName));
-                }
-            }
-            return ExprTupleValue.fromExprValueMap(mapBuilder.build());
+  @Override
+  public ExprValue next() {
+    ExprValue inputValue = input.next();
+    if (STRUCT == inputValue.type()) {
+      Map<String, ExprValue> tupleValue = ExprValueUtils.getTupleValue(inputValue);
+      ImmutableMap.Builder<String, ExprValue> mapBuilder = new Builder<>();
+      for (String bindName : tupleValue.keySet()) {
+        if (mapping.containsKey(DSL.ref(bindName))) {
+          mapBuilder.put(mapping.get(DSL.ref(bindName)).getAttr(), tupleValue.get(bindName));
         } else {
-            return inputValue;
+          mapBuilder.put(bindName, tupleValue.get(bindName));
         }
+      }
+      return ExprTupleValue.fromExprValueMap(mapBuilder.build());
+    } else {
+      return inputValue;
     }
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperator.java
index 6706feeb51..fc5e6054d1 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperator.java
@@ -24,7 +24,6 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.SortOperator.Sorter.SorterBuilder;
 import com.google.common.collect.Iterators;
-import com.google.common.collect.TreeMultiset;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.Iterator;
@@ -47,9 +46,18 @@ public class SortOperator extends PhysicalPlan {
   private final PhysicalPlan input;
   private final Integer count;
   private final List<Pair<SortOption, Expression>> sortList;
-  @EqualsAndHashCode.Exclude private final Sorter sorter;
-  @EqualsAndHashCode.Exclude private Iterator<ExprValue> iterator;
+  @EqualsAndHashCode.Exclude
+  private final Sorter sorter;
+  @EqualsAndHashCode.Exclude
+  private Iterator<ExprValue> iterator;
 
+  /**
+   * Sort Operator Constructor.
+   * @param input input {@link PhysicalPlan}
+   * @param count how many sorted result should been return
+   * @param sortList list of sort sort field.
+   *                 The sort field is specified by the {@link Expression} with {@link SortOption}
+   */
   public SortOperator(
       PhysicalPlan input, Integer count, List<Pair<SortOption, Expression>> sortList) {
     this.input = input;
@@ -111,7 +119,8 @@ public ExprValue next() {
 
   @Builder
   public static class Sorter implements Comparator<ExprValue> {
-    @Singular private final List<Pair<Expression, Comparator<ExprValue>>> comparators;
+    @Singular
+    private final List<Pair<Expression, Comparator<ExprValue>>> comparators;
 
     @Override
     public int compare(ExprValue o1, ExprValue o2) {
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/StorageEngine.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/StorageEngine.java
index 68da18d536..a9eb5fee7e 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/StorageEngine.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/StorageEngine.java
@@ -16,12 +16,12 @@
 package com.amazon.opendistroforelasticsearch.sql.storage;
 
 /**
- * Storage engine for different storage to provide data access API implementation
+ * Storage engine for different storage to provide data access API implementation.
  */
 public interface StorageEngine {
 
-    /**
-     * Get {@link Table} from storage engine.
-     */
-    Table getTable(String name);
+  /**
+   * Get {@link Table} from storage engine.
+   */
+  Table getTable(String name);
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/Table.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/Table.java
index 0d3b04c232..cec317dd59 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/Table.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/Table.java
@@ -18,24 +18,24 @@
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlan;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
-
 import java.util.Map;
 
 /**
- * Table
+ * Table.
  */
 public interface Table {
 
-    /**
-     * Get the {@link ExprType} for each field in the table.
-     */
-    Map<String, ExprType> getFieldTypes();
+  /**
+   * Get the {@link ExprType} for each field in the table.
+   */
+  Map<String, ExprType> getFieldTypes();
 
-    /**
-     * Implement a {@link LogicalPlan} by {@link PhysicalPlan} in storage engine.
-     * @param plan  logical plan
-     * @return      physical plan
-     */
-    PhysicalPlan implement(LogicalPlan plan);
+  /**
+   * Implement a {@link LogicalPlan} by {@link PhysicalPlan} in storage engine.
+   *
+   * @param plan logical plan
+   * @return physical plan
+   */
+  PhysicalPlan implement(LogicalPlan plan);
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperator.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperator.java
index 45693adb3f..bcc5a8cab2 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperator.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperator.java
@@ -18,7 +18,6 @@
 
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlanNodeVisitor;
-
 import java.util.Collections;
 import java.util.List;
 
@@ -28,14 +27,14 @@
  */
 public abstract class TableScanOperator extends PhysicalPlan {
 
-    @Override
-    public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
-        return visitor.visitTableScan(this, context);
-    }
+  @Override
+  public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
+    return visitor.visitTableScan(this, context);
+  }
 
-    @Override
-    public List<PhysicalPlan> getChild() {
-        return Collections.emptyList();
-    }
+  @Override
+  public List<PhysicalPlan> getChild() {
+    return Collections.emptyList();
+  }
 
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTuple.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTuple.java
index a102d82dad..3d1d0aba74 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTuple.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTuple.java
@@ -27,27 +27,27 @@
  * e.g. The operation output column name is bindingName, the value is the ExprValue.
  */
 public abstract class BindingTuple implements Environment<Expression, ExprValue> {
-    public static BindingTuple EMPTY = new BindingTuple() {
-        @Override
-        public ExprValue resolve(ReferenceExpression ref) {
-            return ExprMissingValue.of();
-        }
-    };
-
-    /**
-     * Resolve {@link Expression} in the BindingTuple environment.
-     */
+  public static BindingTuple EMPTY = new BindingTuple() {
     @Override
-    public ExprValue resolve(Expression var) {
-        if (var instanceof ReferenceExpression) {
-            return resolve(((ReferenceExpression) var));
-        } else {
-            throw new ExpressionEvaluationException(String.format("can resolve expression: %s", var));
-        }
+    public ExprValue resolve(ReferenceExpression ref) {
+      return ExprMissingValue.of();
+    }
+  };
+
+  /**
+   * Resolve {@link Expression} in the BindingTuple environment.
+   */
+  @Override
+  public ExprValue resolve(Expression var) {
+    if (var instanceof ReferenceExpression) {
+      return resolve(((ReferenceExpression) var));
+    } else {
+      throw new ExpressionEvaluationException(String.format("can resolve expression: %s", var));
     }
+  }
 
-    /**
-     * Resolve the {@link ReferenceExpression} in BindingTuple context.
-     */
-    public abstract ExprValue resolve(ReferenceExpression ref);
+  /**
+   * Resolve the {@link ReferenceExpression} in BindingTuple context.
+   */
+  public abstract ExprValue resolve(ReferenceExpression ref);
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/LazyBindingTuple.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/LazyBindingTuple.java
index 4aa19293d4..f5e29594b9 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/LazyBindingTuple.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/LazyBindingTuple.java
@@ -25,10 +25,10 @@
  */
 @RequiredArgsConstructor
 public class LazyBindingTuple extends BindingTuple {
-    private final Function<String, ExprValue> lazyBinding;
+  private final Function<String, ExprValue> lazyBinding;
 
-    @Override
-    public ExprValue resolve(ReferenceExpression ref) {
-        return lazyBinding.apply(ref.getAttr());
-    }
+  @Override
+  public ExprValue resolve(ReferenceExpression ref) {
+    return lazyBinding.apply(ref.getAttr());
+  }
 }
diff --git a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/utils/ExpressionUtils.java b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/utils/ExpressionUtils.java
index 313674adfc..dcb8b10239 100644
--- a/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/utils/ExpressionUtils.java
+++ b/core/src/main/java/com/amazon/opendistroforelasticsearch/sql/utils/ExpressionUtils.java
@@ -16,10 +16,9 @@
 package com.amazon.opendistroforelasticsearch.sql.utils;
 
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
-import lombok.experimental.UtilityClass;
-
 import java.util.List;
 import java.util.stream.Collectors;
+import lombok.experimental.UtilityClass;
 
 /**
  * Utils for {@link Expression}.
@@ -27,10 +26,10 @@
 @UtilityClass
 public class ExpressionUtils {
 
-    /**
-     * Format the list of {@link Expression}
-     */
-    public static String format(List<Expression> expressionList) {
-        return expressionList.stream().map(Expression::toString).collect(Collectors.joining(","));
-    }
+  /**
+   * Format the list of {@link Expression}.
+   */
+  public static String format(List<Expression> expressionList) {
+    return expressionList.stream().map(Expression::toString).collect(Collectors.joining(","));
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContextTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContextTest.java
index 22dd81e2b7..225d962185 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContextTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalysisContextTest.java
@@ -15,34 +15,36 @@
 
 package com.amazon.opendistroforelasticsearch.sql.analysis;
 
-import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
-import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
 
 class AnalysisContextTest {
 
-    private final AnalysisContext context = new AnalysisContext();
-
-    @Test
-    public void rootEnvironmentShouldBeThereInitially() {
-        assertNotNull(context.peek());
-    }
-
-    @Test
-    public void pushAndPopEnvironmentShouldPass() {
-        context.push();
-        context.pop();
-    }
-
-    @Test
-    public void popRootEnvironmentShouldPass() {
-        context.pop();
-    }
-
-    @Test
-    public void popEmptyEnvironmentStackShouldFail() {
-        context.pop();
-        NullPointerException exception = assertThrows(NullPointerException.class, () -> context.pop());
-        assertEquals("Fail to pop context due to no environment present", exception.getMessage());
-    }
+  private final AnalysisContext context = new AnalysisContext();
+
+  @Test
+  public void rootEnvironmentShouldBeThereInitially() {
+    assertNotNull(context.peek());
+  }
+
+  @Test
+  public void pushAndPopEnvironmentShouldPass() {
+    context.push();
+    context.pop();
+  }
+
+  @Test
+  public void popRootEnvironmentShouldPass() {
+    context.pop();
+  }
+
+  @Test
+  public void popEmptyEnvironmentStackShouldFail() {
+    context.pop();
+    NullPointerException exception = assertThrows(NullPointerException.class, () -> context.pop());
+    assertEquals("Fail to pop context due to no environment present", exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalyzerTestBase.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalyzerTestBase.java
index 7f66b8fb9d..6bc67bca91 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalyzerTestBase.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/AnalyzerTestBase.java
@@ -40,15 +40,20 @@
 @ContextConfiguration(classes = {ExpressionConfig.class, AnalyzerTestBase.class, TestConfig.class})
 public class AnalyzerTestBase {
 
-  @Autowired protected DSL dsl;
+  @Autowired
+  protected DSL dsl;
 
-  @Autowired protected AnalysisContext analysisContext;
+  @Autowired
+  protected AnalysisContext analysisContext;
 
-  @Autowired protected ExpressionAnalyzer expressionAnalyzer;
+  @Autowired
+  protected ExpressionAnalyzer expressionAnalyzer;
 
-  @Autowired protected Analyzer analyzer;
+  @Autowired
+  protected Analyzer analyzer;
 
-  @Autowired protected Environment<Expression, ExprType> typeEnv;
+  @Autowired
+  protected Environment<Expression, ExprType> typeEnv;
 
   @Bean
   protected Analyzer analyzer(ExpressionAnalyzer expressionAnalyzer, StorageEngine engine) {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzerTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzerTest.java
index 84986b8097..9aff7ba030 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzerTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/ExpressionAnalyzerTest.java
@@ -15,6 +15,12 @@
 
 package com.amazon.opendistroforelasticsearch.sql.analysis;
 
+import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.field;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.UnresolvedExpression;
 import com.amazon.opendistroforelasticsearch.sql.exception.SemanticCheckException;
@@ -22,58 +28,54 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import org.junit.jupiter.api.Test;
 
-import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.field;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
 
 class ExpressionAnalyzerTest extends AnalyzerTestBase {
 
-    @Test
-    public void equal() {
-        assertAnalyzeEqual(
-                dsl.equal(typeEnv, DSL.ref("integer_value"), DSL.literal(integerValue(1))),
-                AstDSL.equalTo(AstDSL.unresolvedAttr("integer_value"), AstDSL.intLiteral(1))
-        );
-    }
+  @Test
+  public void equal() {
+    assertAnalyzeEqual(
+        dsl.equal(typeEnv, DSL.ref("integer_value"), DSL.literal(integerValue(1))),
+        AstDSL.equalTo(AstDSL.unresolvedAttr("integer_value"), AstDSL.intLiteral(1))
+    );
+  }
 
-    @Test
-    public void and() {
-        assertAnalyzeEqual(
-                dsl.and(typeEnv, DSL.ref("boolean_value"), DSL.literal(LITERAL_TRUE)),
-                AstDSL.and(AstDSL.unresolvedAttr("boolean_value"), AstDSL.booleanLiteral(true))
-        );
-    }
+  @Test
+  public void and() {
+    assertAnalyzeEqual(
+        dsl.and(typeEnv, DSL.ref("boolean_value"), DSL.literal(LITERAL_TRUE)),
+        AstDSL.and(AstDSL.unresolvedAttr("boolean_value"), AstDSL.booleanLiteral(true))
+    );
+  }
 
-    @Test
-    public void or() {
-        assertAnalyzeEqual(
-            dsl.or(typeEnv, DSL.ref("boolean_value"), DSL.literal(LITERAL_TRUE)),
-            AstDSL.or(AstDSL.unresolvedAttr("boolean_value"), AstDSL.booleanLiteral(true))
-        );
-    }
+  @Test
+  public void or() {
+    assertAnalyzeEqual(
+        dsl.or(typeEnv, DSL.ref("boolean_value"), DSL.literal(LITERAL_TRUE)),
+        AstDSL.or(AstDSL.unresolvedAttr("boolean_value"), AstDSL.booleanLiteral(true))
+    );
+  }
 
-    @Test
-    public void undefined_var_semantic_check_failed() {
-        SemanticCheckException exception = assertThrows(SemanticCheckException.class,
-                () -> analyze(AstDSL.and(AstDSL.unresolvedAttr("undefined_field"), AstDSL.booleanLiteral(true))));
-        assertEquals("can't resolve expression undefined_field in type env", exception.getMessage());
-    }
+  @Test
+  public void undefined_var_semantic_check_failed() {
+    SemanticCheckException exception = assertThrows(SemanticCheckException.class,
+        () -> analyze(
+            AstDSL.and(AstDSL.unresolvedAttr("undefined_field"), AstDSL.booleanLiteral(true))));
+    assertEquals("can't resolve expression undefined_field in type env", exception.getMessage());
+  }
 
-    @Test
-    public void undefined_aggregation_function() {
-        SemanticCheckException exception = assertThrows(SemanticCheckException.class,
-                () -> analyze(AstDSL.aggregate("ESTDC_ERROR", field("integer_value"))));
-        assertEquals("Unsupported aggregation function ESTDC_ERROR", exception.getMessage());
-    }
+  @Test
+  public void undefined_aggregation_function() {
+    SemanticCheckException exception = assertThrows(SemanticCheckException.class,
+        () -> analyze(AstDSL.aggregate("ESTDC_ERROR", field("integer_value"))));
+    assertEquals("Unsupported aggregation function ESTDC_ERROR", exception.getMessage());
+  }
 
-    protected Expression analyze(UnresolvedExpression unresolvedExpression) {
-        return expressionAnalyzer.analyze(unresolvedExpression, analysisContext);
-    }
+  protected Expression analyze(UnresolvedExpression unresolvedExpression) {
+    return expressionAnalyzer.analyze(unresolvedExpression, analysisContext);
+  }
 
-    protected void assertAnalyzeEqual(Expression expected, UnresolvedExpression unresolvedExpression) {
-        assertEquals(expected, analyze(unresolvedExpression));
-    }
+  protected void assertAnalyzeEqual(Expression expected,
+                                    UnresolvedExpression unresolvedExpression) {
+    assertEquals(expected, analyze(unresolvedExpression));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironmentTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironmentTest.java
index d9555c3ca6..ce00697682 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironmentTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/TypeEnvironmentTest.java
@@ -15,6 +15,9 @@
 
 package com.amazon.opendistroforelasticsearch.sql.analysis;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
 import com.amazon.opendistroforelasticsearch.sql.exception.SemanticCheckException;
@@ -22,80 +25,78 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
 public class TypeEnvironmentTest {
 
-    /**
-     * Use context class for push/pop
-     */
-    private AnalysisContext context = new AnalysisContext();
-
-    @Test
-    public void defineFieldSymbolInDifferentEnvironmentsShouldBeAbleToResolve() {
-        // Root environment
-        Expression age = DSL.ref("s.age");
-        environment().define(age, ExprType.INTEGER);
-        assertEquals(ExprType.INTEGER, environment().resolve(age));
-
-        // New environment 1
-        context.push();
-        Expression city = DSL.ref("s.city");
-        environment().define(city, ExprType.STRING);
-        assertEquals(ExprType.INTEGER, environment().resolve(age));
-        assertEquals(ExprType.STRING, environment().resolve(city));
-
-        // New environment 2
-        context.push();
-        Expression manager = DSL.ref("s.manager");
-        environment().define(manager, ExprType.STRUCT);
-        assertEquals(ExprType.INTEGER, environment().resolve(age));
-        assertEquals(ExprType.STRING, environment().resolve(city));
-        assertEquals(ExprType.STRUCT, environment().resolve(manager));
-    }
-
-    @Test
-    public void defineFieldSymbolInDifferentEnvironmentsShouldNotAbleToResolveOncePopped() {
-        // Root environment
-        Expression age = DSL.ref("s.age");
-        environment().define(age, ExprType.INTEGER);
-
-        // New environment
-        context.push();
-        Expression city = DSL.ref("s.city");
-        environment().define(city, ExprType.STRING);
-        Expression manager = DSL.ref("s.manager");
-        environment().define(manager, ExprType.STRUCT);
-        assertEquals(ExprType.INTEGER, environment().resolve(age));
-        assertEquals(ExprType.STRING, environment().resolve(city));
-        assertEquals(ExprType.STRUCT, environment().resolve(manager));
-
-        context.pop();
-        assertEquals(ExprType.INTEGER, environment().resolve(age));
-        SemanticCheckException exception = assertThrows(SemanticCheckException.class, () -> environment().resolve(city));
-        assertEquals("can't resolve expression s.city in type env", exception.getMessage());
-        exception = assertThrows(SemanticCheckException.class, () -> environment().resolve(manager));
-        assertEquals("can't resolve expression s.manager in type env", exception.getMessage());
-    }
-
-    @Test
-    public void resolveLiteralInEnvFailed() {
-        SemanticCheckException exception = assertThrows(SemanticCheckException.class,
-                () -> environment().resolve(DSL.literal(ExprValueUtils.integerValue(1))));
-        assertEquals("can't resolve expression 1 in type env", exception.getMessage());
-    }
-
-
-    @Test
-    public void defineLiteralInEnvIsIllegal() {
-        IllegalArgumentException exception = assertThrows(IllegalArgumentException.class,
-                () -> environment().define(DSL.literal(ExprValueUtils.integerValue(1)), ExprType.INTEGER));
-        assertEquals("only support define reference, unexpected expression 1", exception.getMessage());
-    }
-
-    private TypeEnvironment environment() {
-        return context.peek();
-    }
+  /**
+   * Use context class for push/pop.
+   */
+  private AnalysisContext context = new AnalysisContext();
+
+  @Test
+  public void defineFieldSymbolInDifferentEnvironmentsShouldBeAbleToResolve() {
+    // Root environment
+    Expression age = DSL.ref("s.age");
+    environment().define(age, ExprType.INTEGER);
+    assertEquals(ExprType.INTEGER, environment().resolve(age));
+
+    // New environment 1
+    context.push();
+    Expression city = DSL.ref("s.city");
+    environment().define(city, ExprType.STRING);
+    assertEquals(ExprType.INTEGER, environment().resolve(age));
+    assertEquals(ExprType.STRING, environment().resolve(city));
+
+    // New environment 2
+    context.push();
+    Expression manager = DSL.ref("s.manager");
+    environment().define(manager, ExprType.STRUCT);
+    assertEquals(ExprType.INTEGER, environment().resolve(age));
+    assertEquals(ExprType.STRING, environment().resolve(city));
+    assertEquals(ExprType.STRUCT, environment().resolve(manager));
+  }
+
+  @Test
+  public void defineFieldSymbolInDifferentEnvironmentsShouldNotAbleToResolveOncePopped() {
+    // Root environment
+    Expression age = DSL.ref("s.age");
+    environment().define(age, ExprType.INTEGER);
+
+    // New environment
+    context.push();
+    Expression city = DSL.ref("s.city");
+    environment().define(city, ExprType.STRING);
+    Expression manager = DSL.ref("s.manager");
+    environment().define(manager, ExprType.STRUCT);
+    assertEquals(ExprType.INTEGER, environment().resolve(age));
+    assertEquals(ExprType.STRING, environment().resolve(city));
+    assertEquals(ExprType.STRUCT, environment().resolve(manager));
+
+    context.pop();
+    assertEquals(ExprType.INTEGER, environment().resolve(age));
+    SemanticCheckException exception =
+        assertThrows(SemanticCheckException.class, () -> environment().resolve(city));
+    assertEquals("can't resolve expression s.city in type env", exception.getMessage());
+    exception = assertThrows(SemanticCheckException.class, () -> environment().resolve(manager));
+    assertEquals("can't resolve expression s.manager in type env", exception.getMessage());
+  }
+
+  @Test
+  public void resolveLiteralInEnvFailed() {
+    SemanticCheckException exception = assertThrows(SemanticCheckException.class,
+        () -> environment().resolve(DSL.literal(ExprValueUtils.integerValue(1))));
+    assertEquals("can't resolve expression 1 in type env", exception.getMessage());
+  }
+
+
+  @Test
+  public void defineLiteralInEnvIsIllegal() {
+    IllegalArgumentException exception = assertThrows(IllegalArgumentException.class,
+        () -> environment().define(DSL.literal(ExprValueUtils.integerValue(1)), ExprType.INTEGER));
+    assertEquals("only support define reference, unexpected expression 1", exception.getMessage());
+  }
+
+  private TypeEnvironment environment() {
+    return context.peek();
+  }
 
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTableTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTableTest.java
index a44e443d1c..d04456abf5 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTableTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/analysis/symbol/SymbolTableTest.java
@@ -15,12 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.analysis.symbol;
 
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
-import org.junit.jupiter.api.Test;
-
-import java.util.Map;
-import java.util.Optional;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.BOOLEAN;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.INTEGER;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.STRING;
@@ -33,54 +27,61 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import java.util.Map;
+import java.util.Optional;
+import org.junit.jupiter.api.Test;
 
-public class SymbolTableTest {
-
-    private final SymbolTable symbolTable = new SymbolTable();
-
-    @Test
-    public void defineFieldSymbolShouldBeAbleToResolve() {
-        defineSymbolShouldBeAbleToResolve(new Symbol(Namespace.FIELD_NAME, "age"), INTEGER);
-    }
-
-
-    @Test
-    public void defineFieldSymbolShouldBeAbleToResolveByPrefix() {
-        symbolTable.store(new Symbol(Namespace.FIELD_NAME, "s.projects.active"), BOOLEAN);
-        symbolTable.store(new Symbol(Namespace.FIELD_NAME, "s.address"), STRING);
-        symbolTable.store(new Symbol(Namespace.FIELD_NAME, "s.manager.name"), STRING);
-
-        Map<String, ExprType> typeByName = symbolTable.lookupByPrefix(new Symbol(Namespace.FIELD_NAME, "s.projects"));
-
-        assertThat(
-                typeByName,
-                allOf(
-                        aMapWithSize(1),
-                        hasEntry("s.projects.active", BOOLEAN)
-                )
-        );
-    }
-
-    @Test
-    public void failedToResolveSymbolNoNamespaceMatched() {
-        symbolTable.store(new Symbol(Namespace.FUNCTION_NAME, "customFunction"), BOOLEAN);
-        assertFalse(symbolTable.lookup(new Symbol(Namespace.FIELD_NAME, "s.projects")).isPresent());
-
-        assertThat(symbolTable.lookupByPrefix(new Symbol(Namespace.FIELD_NAME, "s.projects")), anEmptyMap());
-    }
-
-    @Test
-    public void isEmpty() {
-        symbolTable.store(new Symbol(Namespace.FUNCTION_NAME, "customFunction"), BOOLEAN);
-        assertTrue(symbolTable.isEmpty(Namespace.FIELD_NAME));
-    }
 
-    private void defineSymbolShouldBeAbleToResolve(Symbol symbol, ExprType expectedType) {
-        symbolTable.store(symbol, expectedType);
+public class SymbolTableTest {
 
-        Optional<ExprType> actualType = symbolTable.lookup(symbol);
-        assertTrue(actualType.isPresent());
-        assertEquals(expectedType, actualType.get());
-    }
+  private final SymbolTable symbolTable = new SymbolTable();
+
+  @Test
+  public void defineFieldSymbolShouldBeAbleToResolve() {
+    defineSymbolShouldBeAbleToResolve(new Symbol(Namespace.FIELD_NAME, "age"), INTEGER);
+  }
+
+
+  @Test
+  public void defineFieldSymbolShouldBeAbleToResolveByPrefix() {
+    symbolTable.store(new Symbol(Namespace.FIELD_NAME, "s.projects.active"), BOOLEAN);
+    symbolTable.store(new Symbol(Namespace.FIELD_NAME, "s.address"), STRING);
+    symbolTable.store(new Symbol(Namespace.FIELD_NAME, "s.manager.name"), STRING);
+
+    Map<String, ExprType> typeByName =
+        symbolTable.lookupByPrefix(new Symbol(Namespace.FIELD_NAME, "s.projects"));
+
+    assertThat(
+        typeByName,
+        allOf(
+            aMapWithSize(1),
+            hasEntry("s.projects.active", BOOLEAN)
+        )
+    );
+  }
+
+  @Test
+  public void failedToResolveSymbolNoNamespaceMatched() {
+    symbolTable.store(new Symbol(Namespace.FUNCTION_NAME, "customFunction"), BOOLEAN);
+    assertFalse(symbolTable.lookup(new Symbol(Namespace.FIELD_NAME, "s.projects")).isPresent());
+
+    assertThat(symbolTable.lookupByPrefix(new Symbol(Namespace.FIELD_NAME, "s.projects")),
+        anEmptyMap());
+  }
+
+  @Test
+  public void isEmpty() {
+    symbolTable.store(new Symbol(Namespace.FUNCTION_NAME, "customFunction"), BOOLEAN);
+    assertTrue(symbolTable.isEmpty(Namespace.FIELD_NAME));
+  }
+
+  private void defineSymbolShouldBeAbleToResolve(Symbol symbol, ExprType expectedType) {
+    symbolTable.store(symbol, expectedType);
+
+    Optional<ExprType> actualType = symbolTable.lookup(symbol);
+    assertTrue(actualType.isPresent());
+    assertEquals(expectedType, actualType.get());
+  }
 
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/config/TestConfig.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/config/TestConfig.java
index 025fc0616b..1bbf6d2d98 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/config/TestConfig.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/config/TestConfig.java
@@ -28,76 +28,76 @@
 import com.amazon.opendistroforelasticsearch.sql.storage.StorageEngine;
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import com.google.common.collect.ImmutableMap;
+import java.util.Map;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
-import java.util.Map;
-
 /**
  * Configuration will be used for UT.
  */
 @Configuration
 public class TestConfig {
-    public static final String INT_TYPE_NULL_VALUE_FIELD = "int_null_value";
-    public static final String INT_TYPE_MISSING_VALUE_FIELD = "int_missing_value";
-    public static final String BOOL_TYPE_NULL_VALUE_FIELD = "null_value_boolean";
-    public static final String BOOL_TYPE_MISSING_VALUE_FIELD = "missing_value_boolean";
+  public static final String INT_TYPE_NULL_VALUE_FIELD = "int_null_value";
+  public static final String INT_TYPE_MISSING_VALUE_FIELD = "int_missing_value";
+  public static final String BOOL_TYPE_NULL_VALUE_FIELD = "null_value_boolean";
+  public static final String BOOL_TYPE_MISSING_VALUE_FIELD = "missing_value_boolean";
 
-    private static Map<String, ExprType> typeMapping = new ImmutableMap.Builder<String, ExprType>()
-            .put("integer_value", ExprType.INTEGER)
-            .put(INT_TYPE_NULL_VALUE_FIELD, ExprType.INTEGER)
-            .put(INT_TYPE_MISSING_VALUE_FIELD, ExprType.INTEGER)
-            .put("long_value", ExprType.LONG)
-            .put("float_value", ExprType.FLOAT)
-            .put("double_value", ExprType.DOUBLE)
-            .put("boolean_value", ExprType.BOOLEAN)
-            .put(BOOL_TYPE_NULL_VALUE_FIELD, ExprType.BOOLEAN)
-            .put(BOOL_TYPE_MISSING_VALUE_FIELD, ExprType.BOOLEAN)
-            .put("string_value", ExprType.STRING)
-            .put("struct_value", ExprType.STRUCT)
-            .put("array_value", ExprType.ARRAY)
-            .build();
+  private static Map<String, ExprType> typeMapping = new ImmutableMap.Builder<String, ExprType>()
+      .put("integer_value", ExprType.INTEGER)
+      .put(INT_TYPE_NULL_VALUE_FIELD, ExprType.INTEGER)
+      .put(INT_TYPE_MISSING_VALUE_FIELD, ExprType.INTEGER)
+      .put("long_value", ExprType.LONG)
+      .put("float_value", ExprType.FLOAT)
+      .put("double_value", ExprType.DOUBLE)
+      .put("boolean_value", ExprType.BOOLEAN)
+      .put(BOOL_TYPE_NULL_VALUE_FIELD, ExprType.BOOLEAN)
+      .put(BOOL_TYPE_MISSING_VALUE_FIELD, ExprType.BOOLEAN)
+      .put("string_value", ExprType.STRING)
+      .put("struct_value", ExprType.STRUCT)
+      .put("array_value", ExprType.ARRAY)
+      .build();
 
-    @Bean
-    protected StorageEngine storageEngine() {
-        return new StorageEngine() {
-            @Override
-            public Table getTable(String name) {
-                return new Table() {
-                    @Override
-                    public Map<String, ExprType> getFieldTypes() {
-                        return typeMapping;
-                    }
+  @Bean
+  protected StorageEngine storageEngine() {
+    return new StorageEngine() {
+      @Override
+      public Table getTable(String name) {
+        return new Table() {
+          @Override
+          public Map<String, ExprType> getFieldTypes() {
+            return typeMapping;
+          }
 
-                    @Override
-                    public PhysicalPlan implement(LogicalPlan plan) {
-                        throw new UnsupportedOperationException();
-                    }
-                };
-            }
+          @Override
+          public PhysicalPlan implement(LogicalPlan plan) {
+            throw new UnsupportedOperationException();
+          }
         };
-    }
+      }
+    };
+  }
 
 
-    @Bean
-    protected SymbolTable symbolTable() {
-        SymbolTable symbolTable = new SymbolTable();
-        typeMapping.entrySet()
-                .forEach(
-                        entry -> symbolTable.store(new Symbol(Namespace.FIELD_NAME, entry.getKey()), entry.getValue()));
-        return symbolTable;
-    }
+  @Bean
+  protected SymbolTable symbolTable() {
+    SymbolTable symbolTable = new SymbolTable();
+    typeMapping.entrySet()
+        .forEach(
+            entry -> symbolTable
+                .store(new Symbol(Namespace.FIELD_NAME, entry.getKey()), entry.getValue()));
+    return symbolTable;
+  }
 
-    @Bean
-    protected Environment<Expression, ExprType> typeEnv() {
-        return var -> {
-            if (var instanceof ReferenceExpression) {
-                ReferenceExpression refExpr = (ReferenceExpression) var;
-                if (typeMapping.containsKey(refExpr.getAttr())) {
-                    return typeMapping.get(refExpr.getAttr());
-                }
-            }
-            throw new ExpressionEvaluationException("type resolved failed");
-        };
-    }
+  @Bean
+  protected Environment<Expression, ExprType> typeEnv() {
+    return var -> {
+      if (var instanceof ReferenceExpression) {
+        ReferenceExpression refExpr = (ReferenceExpression) var;
+        if (typeMapping.containsKey(refExpr.getAttr())) {
+          return typeMapping.get(refExpr.getAttr());
+        }
+      }
+      throw new ExpressionEvaluationException("type resolved failed");
+    };
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValueTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValueTest.java
index 3393444dd2..7fec1d002d 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValueTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprMissingValueTest.java
@@ -15,33 +15,33 @@
 
 package com.amazon.opendistroforelasticsearch.sql.data.model;
 
-import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
-import org.junit.jupiter.api.Test;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
+import org.junit.jupiter.api.Test;
+
 
 class ExprMissingValueTest {
 
-    @Test
-    public void test_is_missing() {
-        assertTrue(LITERAL_MISSING.isMissing());
-    }
-
-    @Test
-    public void getValue() {
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> LITERAL_MISSING.value());
-        assertEquals("invalid to call value operation on missing value", exception.getMessage());
-    }
-
-    @Test
-    public void getType() {
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> LITERAL_MISSING.type());
-        assertEquals("invalid to call type operation on missing value", exception.getMessage());
-    }
+  @Test
+  public void test_is_missing() {
+    assertTrue(LITERAL_MISSING.isMissing());
+  }
+
+  @Test
+  public void getValue() {
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> LITERAL_MISSING.value());
+    assertEquals("invalid to call value operation on missing value", exception.getMessage());
+  }
+
+  @Test
+  public void getType() {
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> LITERAL_MISSING.type());
+    assertEquals("invalid to call type operation on missing value", exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValueTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValueTest.java
index d16f2d6bc2..db0bd4041b 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValueTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprNullValueTest.java
@@ -15,31 +15,31 @@
 
 package com.amazon.opendistroforelasticsearch.sql.data.model;
 
-import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
-import org.junit.jupiter.api.Test;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
+import org.junit.jupiter.api.Test;
+
 public class ExprNullValueTest {
 
-    @Test
-    public void test_is_null() {
-        assertTrue(LITERAL_NULL.isNull());
-    }
+  @Test
+  public void test_is_null() {
+    assertTrue(LITERAL_NULL.isNull());
+  }
 
-    @Test
-    public void getValue() {
-        assertNull(LITERAL_NULL.value());
-    }
+  @Test
+  public void getValue() {
+    assertNull(LITERAL_NULL.value());
+  }
 
-    @Test
-    public void getType() {
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> LITERAL_NULL.type());
-        assertEquals("invalid to call type operation on null value", exception.getMessage());
-    }
+  @Test
+  public void getType() {
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> LITERAL_NULL.type());
+    assertEquals("invalid to call type operation on null value", exception.getMessage());
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValueTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValueTest.java
index 0004915b17..4ed62bf066 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValueTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprTupleValueTest.java
@@ -22,24 +22,25 @@
 import org.junit.jupiter.api.Test;
 
 class ExprTupleValueTest {
-    @Test
-    public void equal_to_itself() {
-        ExprValue tupleValue = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2));
-        assertTrue(tupleValue.equals(tupleValue));
-    }
+  @Test
+  public void equal_to_itself() {
+    ExprValue tupleValue = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2));
+    assertTrue(tupleValue.equals(tupleValue));
+  }
 
-    @Test
-    public void tuple_compare_int() {
-        ExprValue tupleValue = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2));
-        ExprValue intValue = ExprValueUtils.integerValue(10);
-        assertFalse(tupleValue.equals(intValue));
-    }
+  @Test
+  public void tuple_compare_int() {
+    ExprValue tupleValue = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2));
+    ExprValue intValue = ExprValueUtils.integerValue(10);
+    assertFalse(tupleValue.equals(intValue));
+  }
 
-    @Test
-    public void compre_tuple_with_different_size() {
-        ExprValue tupleValue1 = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2));
-        ExprValue tupleValue2 = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2, "float_value", 1f));
-        assertFalse(tupleValue1.equals(tupleValue2));
-        assertFalse(tupleValue2.equals(tupleValue1));
-    }
+  @Test
+  public void compre_tuple_with_different_size() {
+    ExprValue tupleValue1 = ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2));
+    ExprValue tupleValue2 =
+        ExprValueUtils.tupleValue(ImmutableMap.of("integer_value", 2, "float_value", 1f));
+    assertFalse(tupleValue1.equals(tupleValue2));
+    assertFalse(tupleValue2.equals(tupleValue1));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtilsTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtilsTest.java
index 26ef90bc6b..7daa64b090 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtilsTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/model/ExprValueUtilsTest.java
@@ -15,17 +15,16 @@
 
 package com.amazon.opendistroforelasticsearch.sql.data.model;
 
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
 import com.amazon.opendistroforelasticsearch.sql.storage.bindingtuple.BindingTuple;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
-import org.junit.jupiter.api.DisplayName;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
-
 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -34,139 +33,157 @@
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNotEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 @DisplayName("Test Expression Value Utils")
 public class ExprValueUtilsTest {
-    private static List<ExprValue> numberValues = Stream.of(1, 1L, 1f, 1D)
-            .map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
-    private static List<ExprValue> nonNumberValues = Stream.of("1", true, Arrays.asList(1),
-            ImmutableMap.of("1", 1)).map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
-    private static List<ExprValue> allValues = Lists.newArrayList(Iterables.concat(numberValues, nonNumberValues));
-
-    private static List<Function<ExprValue, Object>> numberValueExtractor = Arrays.asList(
-            ExprValueUtils::getIntegerValue,
-            ExprValueUtils::getLongValue,
-            ExprValueUtils::getFloatValue,
-            ExprValueUtils::getDoubleValue);
-    private static List<Function<ExprValue, Object>> nonNumberValueExtractor = Arrays.asList(
-            ExprValueUtils::getStringValue,
-            ExprValueUtils::getBooleanValue,
-            ExprValueUtils::getCollectionValue,
-            ExprValueUtils::getTupleValue);
-    private static List<Function<ExprValue, Object>> allValueExtractor = Lists.newArrayList(
-            Iterables.concat(numberValueExtractor, nonNumberValueExtractor));
-
-    private static List<ExprType> numberTypes = Arrays.asList(ExprType.INTEGER, ExprType.LONG, ExprType.FLOAT,
-            ExprType.DOUBLE);
-    private static List<ExprType> nonNumberTypes = Arrays.asList(ExprType.STRING, ExprType.BOOLEAN, ExprType.ARRAY,
-            ExprType.STRUCT);
-    private static List<ExprType> allTypes = Lists.newArrayList(Iterables.concat(numberTypes, nonNumberTypes));
-
-    private static Stream<Arguments> getValueTestArgumentStream() {
-        List<Object> expectedValues = Arrays.asList(1, 1L, 1f, 1D, "1", true,
-                Arrays.asList(integerValue(1)),
-                ImmutableMap.of("1", integerValue(1)));
-        Stream.Builder<Arguments> builder = Stream.builder();
-        for (int i = 0; i < expectedValues.size(); i++) {
-            builder.add(Arguments.of(
-                    allValues.get(i),
-                    allValueExtractor.get(i),
-                    expectedValues.get(i)));
-        }
-        return builder.build();
-    }
-
-    private static Stream<Arguments> getTypeTestArgumentStream() {
-        Stream.Builder<Arguments> builder = Stream.builder();
-        for (int i = 0; i < allValues.size(); i++) {
-            builder.add(Arguments.of(
-                    allValues.get(i),
-                    allTypes.get(i)));
-        }
-        return builder.build();
-    }
-
-    private static Stream<Arguments> invalidGetNumberValueArgumentStream() {
-        return Lists.cartesianProduct(nonNumberValues, numberValueExtractor)
-                .stream()
-                .map(list -> Arguments.of(list.get(0), list.get(1)));
-    }
-
-    @SuppressWarnings("unchecked")
-    private static Stream<Arguments> invalidConvert() {
-        List<Map.Entry<Function<ExprValue, Object>, ExprType>> extractorWithTypeList = new ArrayList<>();
-        for (int i = 0; i < nonNumberValueExtractor.size(); i++) {
-            extractorWithTypeList.add(
-                    new AbstractMap.SimpleEntry<>(nonNumberValueExtractor.get(i), nonNumberTypes.get(i)));
-        }
-        return Lists.cartesianProduct(allValues, extractorWithTypeList)
-                .stream()
-                .filter(list -> {
-                    ExprValue value = (ExprValue) list.get(0);
-                    Map.Entry<Function<ExprValue, Object>, ExprType> entry = (Map.Entry<Function<ExprValue, Object>,
-                            ExprType>) list
-                            .get(1);
-                    return entry.getValue() != value.type();
-                })
-                .map(list -> {
-                    Map.Entry<Function<ExprValue, Object>, ExprType> entry = (Map.Entry<Function<ExprValue, Object>,
-                            ExprType>) list
-                            .get(1);
-                    return Arguments.of(list.get(0), entry.getKey(), entry.getValue());
-                });
+  private static List<ExprValue> numberValues = Stream.of(1, 1L, 1f, 1D)
+      .map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
+  private static List<ExprValue> nonNumberValues = Stream.of("1", true, Arrays.asList(1),
+      ImmutableMap.of("1", 1)).map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
+  private static List<ExprValue> allValues =
+      Lists.newArrayList(Iterables.concat(numberValues, nonNumberValues));
+
+  private static List<Function<ExprValue, Object>> numberValueExtractor = Arrays.asList(
+      ExprValueUtils::getIntegerValue,
+      ExprValueUtils::getLongValue,
+      ExprValueUtils::getFloatValue,
+      ExprValueUtils::getDoubleValue);
+  private static List<Function<ExprValue, Object>> nonNumberValueExtractor = Arrays.asList(
+      ExprValueUtils::getStringValue,
+      ExprValueUtils::getBooleanValue,
+      ExprValueUtils::getCollectionValue,
+      ExprValueUtils::getTupleValue);
+  private static List<Function<ExprValue, Object>> allValueExtractor = Lists.newArrayList(
+      Iterables.concat(numberValueExtractor, nonNumberValueExtractor));
+
+  private static List<ExprType> numberTypes =
+      Arrays.asList(ExprType.INTEGER, ExprType.LONG, ExprType.FLOAT,
+          ExprType.DOUBLE);
+  private static List<ExprType> nonNumberTypes =
+      Arrays.asList(ExprType.STRING, ExprType.BOOLEAN, ExprType.ARRAY,
+          ExprType.STRUCT);
+  private static List<ExprType> allTypes =
+      Lists.newArrayList(Iterables.concat(numberTypes, nonNumberTypes));
+
+  private static Stream<Arguments> getValueTestArgumentStream() {
+    List<Object> expectedValues = Arrays.asList(1, 1L, 1f, 1D, "1", true,
+        Arrays.asList(integerValue(1)),
+        ImmutableMap.of("1", integerValue(1)));
+    Stream.Builder<Arguments> builder = Stream.builder();
+    for (int i = 0; i < expectedValues.size(); i++) {
+      builder.add(Arguments.of(
+          allValues.get(i),
+          allValueExtractor.get(i),
+          expectedValues.get(i)));
     }
-
-    @ParameterizedTest(name = "the value of ExprValue:{0} is: {2} ")
-    @MethodSource("getValueTestArgumentStream")
-    public void getValue(ExprValue value, Function<ExprValue, Object> extractor, Object expect) {
-        assertEquals(expect, extractor.apply(value));
+    return builder.build();
+  }
+
+  private static Stream<Arguments> getTypeTestArgumentStream() {
+    Stream.Builder<Arguments> builder = Stream.builder();
+    for (int i = 0; i < allValues.size(); i++) {
+      builder.add(Arguments.of(
+          allValues.get(i),
+          allTypes.get(i)));
     }
-
-    @ParameterizedTest(name = "the type of ExprValue:{0} is: {1} ")
-    @MethodSource("getTypeTestArgumentStream")
-    public void getType(ExprValue value, ExprType expectType) {
-        assertEquals(expectType, value.type());
+    return builder.build();
+  }
+
+  private static Stream<Arguments> invalidGetNumberValueArgumentStream() {
+    return Lists.cartesianProduct(nonNumberValues, numberValueExtractor)
+        .stream()
+        .map(list -> Arguments.of(list.get(0), list.get(1)));
+  }
+
+  @SuppressWarnings("unchecked")
+  private static Stream<Arguments> invalidConvert() {
+    List<Map.Entry<Function<ExprValue, Object>, ExprType>> extractorWithTypeList =
+        new ArrayList<>();
+    for (int i = 0; i < nonNumberValueExtractor.size(); i++) {
+      extractorWithTypeList.add(
+          new AbstractMap.SimpleEntry<>(nonNumberValueExtractor.get(i), nonNumberTypes.get(i)));
     }
-
-    @ParameterizedTest(name = "invalid to get number value of ExprValue:{0}")
-    @MethodSource("invalidGetNumberValueArgumentStream")
-    public void invalidGetNumberValue(ExprValue value, Function<ExprValue, Object> extractor) {
-        Exception exception = assertThrows(ExpressionEvaluationException.class,
-                () -> extractor.apply(value));
-        assertEquals(String.format("invalid to getNumberValue with expression has type of %s", value.type()),
-                exception.getMessage());
-    }
-
-    @ParameterizedTest(name = "invalid convert ExprValue:{0} to ExprType:{2}")
-    @MethodSource("invalidConvert")
-    public void invalidConvert(ExprValue value, Function<ExprValue, Object> extractor, ExprType toType) {
-        Exception exception = assertThrows(ExpressionEvaluationException.class,
-                () -> extractor.apply(value));
-        assertEquals(String.format("invalid to convert expression with type:%s to type:%s", value.type(), toType),
-                exception.getMessage());
-    }
-
-    @Test
-    public void unSupportedObject() {
-        Exception exception = assertThrows(ExpressionEvaluationException.class,
-                () -> ExprValueUtils.fromObjectValue(integerValue(1)));
-        assertEquals("unsupported object class com.amazon.opendistroforelasticsearch.sql.data.model.ExprIntegerValue",
-                exception.getMessage());
-    }
-
-    @Test
-    public void bindingTuples() {
-        for (ExprValue value : allValues) {
-            if (ExprType.STRUCT == value.type()) {
-                assertNotEquals(BindingTuple.EMPTY, value.bindingTuples());
-            } else {
-                assertEquals(BindingTuple.EMPTY, value.bindingTuples());
-            }
-        }
+    return Lists.cartesianProduct(allValues, extractorWithTypeList)
+        .stream()
+        .filter(list -> {
+          ExprValue value = (ExprValue) list.get(0);
+          Map.Entry<Function<ExprValue, Object>, ExprType> entry =
+              (Map.Entry<Function<ExprValue, Object>,
+                  ExprType>) list
+                  .get(1);
+          return entry.getValue() != value.type();
+        })
+        .map(list -> {
+          Map.Entry<Function<ExprValue, Object>, ExprType> entry =
+              (Map.Entry<Function<ExprValue, Object>,
+                  ExprType>) list
+                  .get(1);
+          return Arguments.of(list.get(0), entry.getKey(), entry.getValue());
+        });
+  }
+
+  @ParameterizedTest(name = "the value of ExprValue:{0} is: {2} ")
+  @MethodSource("getValueTestArgumentStream")
+  public void getValue(ExprValue value, Function<ExprValue, Object> extractor, Object expect) {
+    assertEquals(expect, extractor.apply(value));
+  }
+
+  @ParameterizedTest(name = "the type of ExprValue:{0} is: {1} ")
+  @MethodSource("getTypeTestArgumentStream")
+  public void getType(ExprValue value, ExprType expectType) {
+    assertEquals(expectType, value.type());
+  }
+
+  /**
+   * Test Invalid to get number.
+   */
+  @ParameterizedTest(name = "invalid to get number value of ExprValue:{0}")
+  @MethodSource("invalidGetNumberValueArgumentStream")
+  public void invalidGetNumberValue(ExprValue value, Function<ExprValue, Object> extractor) {
+    Exception exception = assertThrows(ExpressionEvaluationException.class,
+        () -> extractor.apply(value));
+    assertEquals(
+        String.format("invalid to getNumberValue with expression has type of %s", value.type()),
+        exception.getMessage());
+  }
+
+  /**
+   * Test Invalid to convert.
+   */
+  @ParameterizedTest(name = "invalid convert ExprValue:{0} to ExprType:{2}")
+  @MethodSource("invalidConvert")
+  public void invalidConvertExprValue(ExprValue value, Function<ExprValue, Object> extractor,
+                                      ExprType toType) {
+    Exception exception = assertThrows(ExpressionEvaluationException.class,
+        () -> extractor.apply(value));
+    assertEquals(String
+            .format("invalid to convert expression with type:%s to type:%s", value.type(), toType),
+        exception.getMessage());
+  }
+
+  @Test
+  public void unSupportedObject() {
+    Exception exception = assertThrows(ExpressionEvaluationException.class,
+        () -> ExprValueUtils.fromObjectValue(integerValue(1)));
+    assertEquals(
+        "unsupported object "
+            + "class com.amazon.opendistroforelasticsearch.sql.data.model.ExprIntegerValue",
+        exception.getMessage());
+  }
+
+  @Test
+  public void bindingTuples() {
+    for (ExprValue value : allValues) {
+      if (ExprType.STRUCT == value.type()) {
+        assertNotEquals(BindingTuple.EMPTY, value.bindingTuples());
+      } else {
+        assertEquals(BindingTuple.EMPTY, value.bindingTuples());
+      }
     }
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ExprValueOrderingTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ExprValueOrderingTest.java
index c837f9b78d..ce81c3662e 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ExprValueOrderingTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ExprValueOrderingTest.java
@@ -42,8 +42,10 @@
 
 @ExtendWith(MockitoExtension.class)
 class ExprValueOrderingTest {
-  @Mock ExprValue left;
-  @Mock ExprValue right;
+  @Mock
+  ExprValue left;
+  @Mock
+  ExprValue right;
 
   @Test
   public void natural() {
@@ -136,9 +138,9 @@ public void natural_order_float_value() {
   @Test
   public void natural_order_long_value() {
     ExprValueOrdering ordering = ExprValueOrdering.natural();
-    assertEquals(1, ordering.compare(longValue(5l), longValue(4l)));
-    assertEquals(0, ordering.compare(longValue(5l), longValue(5l)));
-    assertEquals(-1, ordering.compare(longValue(4l), longValue(5l)));
+    assertEquals(1, ordering.compare(longValue(5L), longValue(4L)));
+    assertEquals(0, ordering.compare(longValue(5L), longValue(5L)));
+    assertEquals(-1, ordering.compare(longValue(4L), longValue(5L)));
   }
 
   @Test
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsFirstExprValueOrderingTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsFirstExprValueOrderingTest.java
index d5916eecf3..84f4c4de99 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsFirstExprValueOrderingTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsFirstExprValueOrderingTest.java
@@ -18,7 +18,7 @@
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import org.junit.jupiter.api.Test;
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsLastExprValueOrderingTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsLastExprValueOrderingTest.java
index a02e1ce774..47251506ad 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsLastExprValueOrderingTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/NullsLastExprValueOrderingTest.java
@@ -18,7 +18,7 @@
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import org.junit.jupiter.api.Test;
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ReverseExprValueOrderingTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ReverseExprValueOrderingTest.java
index 15387f999c..d8e07cc205 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ReverseExprValueOrderingTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/data/utils/ReverseExprValueOrderingTest.java
@@ -16,7 +16,7 @@
 package com.amazon.opendistroforelasticsearch.sql.data.utils;
 
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import org.junit.jupiter.api.Test;
 
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ExpressionTestBase.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ExpressionTestBase.java
index e40303f514..222ef2925e 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ExpressionTestBase.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ExpressionTestBase.java
@@ -15,6 +15,21 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression;
 
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_MISSING_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_MISSING_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_NULL_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.collectionValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.doubleValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.floatValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.longValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.missingValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.nullValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.stringValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.tupleValue;
+
 import com.amazon.opendistroforelasticsearch.sql.config.TestConfig;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
@@ -23,6 +38,8 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.function.BuiltinFunctionName;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import java.util.List;
+import java.util.function.BiFunction;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.context.annotation.Bean;
@@ -30,82 +47,74 @@
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit.jupiter.SpringExtension;
 
-import java.util.List;
-import java.util.function.BiFunction;
-
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_NULL_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.collectionValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.doubleValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.floatValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.longValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.missingValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.nullValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.stringValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.tupleValue;
-
 @Configuration
 @ExtendWith(SpringExtension.class)
-@ContextConfiguration(classes = {ExpressionConfig.class, ExpressionTestBase.class, TestConfig.class})
+@ContextConfiguration(classes = {ExpressionConfig.class, ExpressionTestBase.class,
+    TestConfig.class})
 public class ExpressionTestBase {
-    @Autowired
-    protected DSL dsl;
+  @Autowired
+  protected DSL dsl;
 
-    @Autowired
-    protected Environment<Expression, ExprType> typeEnv;
+  @Autowired
+  protected Environment<Expression, ExprType> typeEnv;
 
-    @Bean
-    protected Environment<Expression, ExprValue> valueEnv() {
-        return var -> {
-            if (var instanceof ReferenceExpression) {
-                switch (((ReferenceExpression) var).getAttr()) {
-                    case "integer_value":
-                        return integerValue(1);
-                    case "long_value":
-                        return longValue(1L);
-                    case "float_value":
-                        return floatValue(1f);
-                    case "double_value":
-                        return doubleValue(1d);
-                    case "boolean_value":
-                        return booleanValue(true);
-                    case "string_value":
-                        return stringValue("str");
-                    case "struct_value":
-                        return tupleValue(ImmutableMap.of("str", 1));
-                    case "array_value":
-                        return collectionValue(ImmutableList.of(1));
-                    case BOOL_TYPE_NULL_VALUE_FIELD:
-                    case INT_TYPE_NULL_VALUE_FIELD:
-                        return nullValue();
-                }
-            }
+  @Bean
+  protected Environment<Expression, ExprValue> valueEnv() {
+    return var -> {
+      if (var instanceof ReferenceExpression) {
+        switch (((ReferenceExpression) var).getAttr()) {
+          case "integer_value":
+            return integerValue(1);
+          case "long_value":
+            return longValue(1L);
+          case "float_value":
+            return floatValue(1f);
+          case "double_value":
+            return doubleValue(1d);
+          case "boolean_value":
+            return booleanValue(true);
+          case "string_value":
+            return stringValue("str");
+          case "struct_value":
+            return tupleValue(ImmutableMap.of("str", 1));
+          case "array_value":
+            return collectionValue(ImmutableList.of(1));
+          case BOOL_TYPE_NULL_VALUE_FIELD:
+          case INT_TYPE_NULL_VALUE_FIELD:
+            return nullValue();
+          case INT_TYPE_MISSING_VALUE_FIELD:
+          case BOOL_TYPE_MISSING_VALUE_FIELD:
             return missingValue();
-        };
-    }
+          default:
+            throw new IllegalArgumentException("undefined reference");
+        }
+      } else {
+        throw new IllegalArgumentException("var must be ReferenceExpression");
+      }
+    };
+  }
 
-    @Bean
-    protected Environment<Expression, ExprType> typeEnv() {
-        return typeEnv;
-    }
+  @Bean
+  protected Environment<Expression, ExprType> typeEnv() {
+    return typeEnv;
+  }
 
-    protected BiFunction<Environment<Expression, ExprType>,
-            List<Expression>, FunctionExpression> functionMapping(BuiltinFunctionName builtinFunctionName) {
-        switch (builtinFunctionName) {
-            case ADD:
-                return (env, expressions) -> dsl.add(env, expressions.get(0), expressions.get(1));
-            case SUBTRACT:
-                return (env, expressions) -> dsl.subtract(env, expressions.get(0), expressions.get(1));
-            case MULTIPLY:
-                return (env, expressions) -> dsl.multiply(env, expressions.get(0), expressions.get(1));
-            case DIVIDE:
-                return (env, expressions) -> dsl.divide(env, expressions.get(0), expressions.get(1));
-            case MODULES:
-                return (env, expressions) -> dsl.module(env, expressions.get(0), expressions.get(1));
-            default:
-                throw new RuntimeException();
-        }
+  protected BiFunction<Environment<Expression, ExprType>,
+      List<Expression>, FunctionExpression> functionMapping(
+      BuiltinFunctionName builtinFunctionName) {
+    switch (builtinFunctionName) {
+      case ADD:
+        return (env, expressions) -> dsl.add(env, expressions.get(0), expressions.get(1));
+      case SUBTRACT:
+        return (env, expressions) -> dsl.subtract(env, expressions.get(0), expressions.get(1));
+      case MULTIPLY:
+        return (env, expressions) -> dsl.multiply(env, expressions.get(0), expressions.get(1));
+      case DIVIDE:
+        return (env, expressions) -> dsl.divide(env, expressions.get(0), expressions.get(1));
+      case MODULES:
+        return (env, expressions) -> dsl.module(env, expressions.get(0), expressions.get(1));
+      default:
+        throw new RuntimeException();
     }
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpressionTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpressionTest.java
index f1bd4a9099..ed6feba7a7 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpressionTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/ReferenceExpressionTest.java
@@ -15,14 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression;
 
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
-import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
-import com.google.common.collect.ImmutableList;
-import com.google.common.collect.ImmutableMap;
-import org.junit.jupiter.api.DisplayNameGeneration;
-import org.junit.jupiter.api.DisplayNameGenerator;
-import org.junit.jupiter.api.Test;
-
 import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_MISSING_VALUE_FIELD;
 import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
@@ -38,33 +30,43 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.api.Test;
+
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 class ReferenceExpressionTest extends ExpressionTestBase {
 
-    @Test
-    public void resolve_value() {
-        assertEquals(integerValue(1), DSL.ref("integer_value").valueOf(valueEnv()));
-        assertEquals(longValue(1L), DSL.ref("long_value").valueOf(valueEnv()));
-        assertEquals(floatValue(1f), DSL.ref("float_value").valueOf(valueEnv()));
-        assertEquals(doubleValue(1d), DSL.ref("double_value").valueOf(valueEnv()));
-        assertEquals(booleanValue(true), DSL.ref("boolean_value").valueOf(valueEnv()));
-        assertEquals(stringValue("str"), DSL.ref("string_value").valueOf(valueEnv()));
-        assertEquals(tupleValue(ImmutableMap.of("str", 1)), DSL.ref("struct_value").valueOf(valueEnv()));
-        assertEquals(collectionValue(ImmutableList.of(1)), DSL.ref("array_value").valueOf(valueEnv()));
-        assertEquals(LITERAL_NULL, DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD).valueOf(valueEnv()));
-        assertEquals(LITERAL_MISSING, DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD).valueOf(valueEnv()));
-    }
+  @Test
+  public void resolve_value() {
+    assertEquals(integerValue(1), DSL.ref("integer_value").valueOf(valueEnv()));
+    assertEquals(longValue(1L), DSL.ref("long_value").valueOf(valueEnv()));
+    assertEquals(floatValue(1f), DSL.ref("float_value").valueOf(valueEnv()));
+    assertEquals(doubleValue(1d), DSL.ref("double_value").valueOf(valueEnv()));
+    assertEquals(booleanValue(true), DSL.ref("boolean_value").valueOf(valueEnv()));
+    assertEquals(stringValue("str"), DSL.ref("string_value").valueOf(valueEnv()));
+    assertEquals(tupleValue(ImmutableMap.of("str", 1)),
+        DSL.ref("struct_value").valueOf(valueEnv()));
+    assertEquals(collectionValue(ImmutableList.of(1)), DSL.ref("array_value").valueOf(valueEnv()));
+    assertEquals(LITERAL_NULL, DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD).valueOf(valueEnv()));
+    assertEquals(LITERAL_MISSING, DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD).valueOf(valueEnv()));
+  }
 
-    @Test
-    public void resolve_type() {
-        assertEquals(ExprType.INTEGER, DSL.ref("integer_value").type(typeEnv()));
-        assertEquals(ExprType.LONG, DSL.ref("long_value").type(typeEnv()));
-        assertEquals(ExprType.FLOAT, DSL.ref("float_value").type(typeEnv()));
-        assertEquals(ExprType.DOUBLE, DSL.ref("double_value").type(typeEnv()));
-        assertEquals(ExprType.BOOLEAN, DSL.ref("boolean_value").type(typeEnv()));
-        assertEquals(ExprType.STRING, DSL.ref("string_value").type(typeEnv()));
-        assertEquals(ExprType.STRUCT, DSL.ref("struct_value").type(typeEnv()));
-        assertEquals(ExprType.ARRAY, DSL.ref("array_value").type(typeEnv()));
-        assertThrows(ExpressionEvaluationException.class, () -> DSL.ref("not_exist_field").type(typeEnv()));
-    }
+  @Test
+  public void resolve_type() {
+    assertEquals(ExprType.INTEGER, DSL.ref("integer_value").type(typeEnv()));
+    assertEquals(ExprType.LONG, DSL.ref("long_value").type(typeEnv()));
+    assertEquals(ExprType.FLOAT, DSL.ref("float_value").type(typeEnv()));
+    assertEquals(ExprType.DOUBLE, DSL.ref("double_value").type(typeEnv()));
+    assertEquals(ExprType.BOOLEAN, DSL.ref("boolean_value").type(typeEnv()));
+    assertEquals(ExprType.STRING, DSL.ref("string_value").type(typeEnv()));
+    assertEquals(ExprType.STRUCT, DSL.ref("struct_value").type(typeEnv()));
+    assertEquals(ExprType.ARRAY, DSL.ref("array_value").type(typeEnv()));
+    assertThrows(ExpressionEvaluationException.class,
+        () -> DSL.ref("not_exist_field").type(typeEnv()));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationTest.java
index 5ddf8db89d..ec42a97b2c 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AggregationTest.java
@@ -15,10 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.aggregation;
 
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.collectionValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.tupleValue;
-
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
 import com.amazon.opendistroforelasticsearch.sql.expression.ExpressionTestBase;
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregatorTest.java
index 31cd295968..a9331217f1 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/AvgAggregatorTest.java
@@ -15,47 +15,50 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.aggregation;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
 import com.amazon.opendistroforelasticsearch.sql.expression.DSL;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 class AvgAggregatorTest extends AggregationTest {
 
-    @Test
-    public void avg_field_expression() {
-        ExprValue result = aggregation(dsl.avg(typeEnv,DSL.ref("integer_value")), tuples);
-        assertEquals(2.5, result.value());
-    }
-
-    @Test
-    public void avg_arithmetic_expression() {
-        ExprValue result = aggregation(dsl.avg(typeEnv,
-                dsl.multiply(typeEnv, DSL.ref("integer_value"), DSL.literal(ExprValueUtils.integerValue(10)))), tuples);
-        assertEquals(25.0, result.value());
-    }
-
-    @Test
-    public void avg_with_missing() {
-        ExprValue result = aggregation(dsl.avg(typeEnv,DSL.ref("integer_value")), tuples_with_null_and_missing);
-        assertTrue(result.isNull());
-    }
-
-    @Test
-    public void avg_with_null() {
-        ExprValue result = aggregation(dsl.avg(typeEnv,DSL.ref("double_value")), tuples_with_null_and_missing);
-        assertTrue(result.isNull());
-    }
-
-    @Test
-    public void valueOf() {
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> dsl.avg(typeEnv, DSL.ref("double_value")).valueOf(valueEnv()));
-        assertEquals("can't evaluate on aggregator: avg", exception.getMessage());
-    }
+  @Test
+  public void avg_field_expression() {
+    ExprValue result = aggregation(dsl.avg(typeEnv, DSL.ref("integer_value")), tuples);
+    assertEquals(2.5, result.value());
+  }
+
+  @Test
+  public void avg_arithmetic_expression() {
+    ExprValue result = aggregation(dsl.avg(typeEnv,
+        dsl.multiply(typeEnv, DSL.ref("integer_value"),
+            DSL.literal(ExprValueUtils.integerValue(10)))), tuples);
+    assertEquals(25.0, result.value());
+  }
+
+  @Test
+  public void avg_with_missing() {
+    ExprValue result =
+        aggregation(dsl.avg(typeEnv, DSL.ref("integer_value")), tuples_with_null_and_missing);
+    assertTrue(result.isNull());
+  }
+
+  @Test
+  public void avg_with_null() {
+    ExprValue result =
+        aggregation(dsl.avg(typeEnv, DSL.ref("double_value")), tuples_with_null_and_missing);
+    assertTrue(result.isNull());
+  }
+
+  @Test
+  public void valueOf() {
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> dsl.avg(typeEnv, DSL.ref("double_value")).valueOf(valueEnv()));
+    assertEquals("can't evaluate on aggregator: avg", exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregatorTest.java
index b98b4ef88e..32196459a4 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/CountAggregatorTest.java
@@ -53,7 +53,8 @@ public void count_double_field_expression() {
   @Test
   public void count_arithmetic_expression() {
     ExprValue result = aggregation(dsl.count(typeEnv,
-        dsl.multiply(typeEnv, DSL.ref("integer_value"), DSL.literal(ExprValueUtils.integerValue(10)))), tuples);
+        dsl.multiply(typeEnv, DSL.ref("integer_value"),
+            DSL.literal(ExprValueUtils.integerValue(10)))), tuples);
     assertEquals(4, result.value());
   }
 
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregatorTest.java
index f7bf317ed3..6774c6627c 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/aggregation/SumAggregatorTest.java
@@ -31,64 +31,70 @@
 
 class SumAggregatorTest extends AggregationTest {
 
-    @Test
-    public void sum_integer_field_expression() {
-        ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("integer_value")), tuples);
-        assertEquals(10, result.value());
-    }
+  @Test
+  public void sum_integer_field_expression() {
+    ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("integer_value")), tuples);
+    assertEquals(10, result.value());
+  }
 
-    @Test
-    public void sum_long_field_expression() {
-        ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("long_value")), tuples);
-        assertEquals(10L, result.value());
-    }
+  @Test
+  public void sum_long_field_expression() {
+    ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("long_value")), tuples);
+    assertEquals(10L, result.value());
+  }
 
-    @Test
-    public void sum_float_field_expression() {
-        ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("float_value")), tuples);
-        assertEquals(10f, result.value());
-    }
+  @Test
+  public void sum_float_field_expression() {
+    ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("float_value")), tuples);
+    assertEquals(10f, result.value());
+  }
 
-    @Test
-    public void sum_double_field_expression() {
-        ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("double_value")), tuples);
-        assertEquals(10d, result.value());
-    }
+  @Test
+  public void sum_double_field_expression() {
+    ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("double_value")), tuples);
+    assertEquals(10d, result.value());
+  }
 
-    @Test
-    public void sum_arithmetic_expression() {
-        ExprValue result = aggregation(dsl.sum(typeEnv,
-                dsl.multiply(typeEnv, DSL.ref("integer_value"), DSL.literal(ExprValueUtils.integerValue(10)))), tuples);
-        assertEquals(100, result.value());
-    }
+  @Test
+  public void sum_arithmetic_expression() {
+    ExprValue result = aggregation(dsl.sum(typeEnv,
+        dsl.multiply(typeEnv, DSL.ref("integer_value"),
+            DSL.literal(ExprValueUtils.integerValue(10)))), tuples);
+    assertEquals(100, result.value());
+  }
 
-    @Test
-    public void sum_string_field_expression() {
-        SumAggregator sumAggregator = new SumAggregator(ImmutableList.of(DSL.ref("string_value")), ExprType.STRING);
-        SumState sumState = sumAggregator.create();
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> sumAggregator
-                        .iterate(ExprValueUtils.tupleValue(ImmutableMap.of("string_value", "m")).bindingTuples(), sumState)
-        );
-        assertEquals("unexpected type [STRING] in sum aggregation", exception.getMessage());
-    }
+  @Test
+  public void sum_string_field_expression() {
+    SumAggregator sumAggregator =
+        new SumAggregator(ImmutableList.of(DSL.ref("string_value")), ExprType.STRING);
+    SumState sumState = sumAggregator.create();
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> sumAggregator
+            .iterate(
+                ExprValueUtils.tupleValue(ImmutableMap.of("string_value", "m")).bindingTuples(),
+                sumState)
+    );
+    assertEquals("unexpected type [STRING] in sum aggregation", exception.getMessage());
+  }
 
-    @Test
-    public void sum_with_missing() {
-        ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("integer_value")), tuples_with_null_and_missing);
-        assertTrue(result.isNull());
-    }
+  @Test
+  public void sum_with_missing() {
+    ExprValue result =
+        aggregation(dsl.sum(typeEnv, DSL.ref("integer_value")), tuples_with_null_and_missing);
+    assertTrue(result.isNull());
+  }
 
-    @Test
-    public void sum_with_null() {
-        ExprValue result = aggregation(dsl.sum(typeEnv, DSL.ref("double_value")), tuples_with_null_and_missing);
-        assertTrue(result.isNull());
-    }
+  @Test
+  public void sum_with_null() {
+    ExprValue result =
+        aggregation(dsl.sum(typeEnv, DSL.ref("double_value")), tuples_with_null_and_missing);
+    assertTrue(result.isNull());
+  }
 
-    @Test
-    public void valueOf() {
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> dsl.sum(typeEnv, DSL.ref("double_value")).valueOf(valueEnv()));
-        assertEquals("can't evaluate on aggregator: sum", exception.getMessage());
-    }
+  @Test
+  public void valueOf() {
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> dsl.sum(typeEnv, DSL.ref("double_value")).valueOf(valueEnv()));
+    assertEquals("can't evaluate on aggregator: sum", exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionNameTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionNameTest.java
index 874dc07bf5..6feeb831b4 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionNameTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionNameTest.java
@@ -15,29 +15,28 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import java.util.Arrays;
 import java.util.stream.Stream;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 class BuiltinFunctionNameTest {
 
-    private static Stream<Arguments> ofArguments() {
-        Stream.Builder<Arguments> builder = Stream.builder();
-        return Arrays.asList(BuiltinFunctionName.values())
-                .stream()
-                .map(functionName -> Arguments.of(functionName.getName().getFunctionName(), functionName));
-    }
+  private static Stream<Arguments> ofArguments() {
+    Stream.Builder<Arguments> builder = Stream.builder();
+    return Arrays.asList(BuiltinFunctionName.values())
+        .stream()
+        .map(functionName -> Arguments.of(functionName.getName().getFunctionName(), functionName));
+  }
 
-    @ParameterizedTest
-    @MethodSource("ofArguments")
-    public void of(String name, BuiltinFunctionName expected) {
-        assertTrue(BuiltinFunctionName.of(name).isPresent());
-        assertEquals(expected, BuiltinFunctionName.of(name).get());
-    }
+  @ParameterizedTest
+  @MethodSource("ofArguments")
+  public void of(String name, BuiltinFunctionName expected) {
+    assertTrue(BuiltinFunctionName.of(name).isPresent());
+    assertEquals(expected, BuiltinFunctionName.of(name).get());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepositoryTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepositoryTest.java
index f53b0efab0..7a540cedfd 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepositoryTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/BuiltinFunctionRepositoryTest.java
@@ -15,88 +15,87 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
 import com.amazon.opendistroforelasticsearch.sql.expression.Expression;
 import com.amazon.opendistroforelasticsearch.sql.expression.env.Environment;
+import java.util.Arrays;
+import java.util.Map;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import java.util.Arrays;
-import java.util.Map;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 class BuiltinFunctionRepositoryTest {
-    @Mock
-    private FunctionResolver mockfunctionResolver;
-    @Mock
-    private Map<FunctionName, FunctionResolver> mockMap;
-    @Mock
-    private FunctionName mockFunctionName;
-    @Mock
-    private FunctionBuilder functionExpressionBuilder;
-    @Mock
-    private FunctionSignature functionSignature;
-    @Mock
-    private Expression mockExpression;
-    @Mock
-    private Environment<Expression, ExprType> emptyEnv;
+  @Mock
+  private FunctionResolver mockfunctionResolver;
+  @Mock
+  private Map<FunctionName, FunctionResolver> mockMap;
+  @Mock
+  private FunctionName mockFunctionName;
+  @Mock
+  private FunctionBuilder functionExpressionBuilder;
+  @Mock
+  private FunctionSignature functionSignature;
+  @Mock
+  private Expression mockExpression;
+  @Mock
+  private Environment<Expression, ExprType> emptyEnv;
 
-    @Test
-    void register() {
-        BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
-        when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName);
-        repo.register(mockfunctionResolver);
+  @Test
+  void register() {
+    BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
+    when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName);
+    repo.register(mockfunctionResolver);
 
-        verify(mockMap, times(1)).put(mockFunctionName, mockfunctionResolver);
-    }
+    verify(mockMap, times(1)).put(mockFunctionName, mockfunctionResolver);
+  }
 
-    @Test
-    void compile() {
-        BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
-        when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName);
-        when(mockfunctionResolver.resolve(any())).thenReturn(functionExpressionBuilder);
-        when(mockMap.containsKey(any())).thenReturn(true);
-        when(mockMap.get(any())).thenReturn(mockfunctionResolver);
-        repo.register(mockfunctionResolver);
+  @Test
+  void compile() {
+    when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName);
+    when(mockfunctionResolver.resolve(any())).thenReturn(functionExpressionBuilder);
+    when(mockMap.containsKey(any())).thenReturn(true);
+    when(mockMap.get(any())).thenReturn(mockfunctionResolver);
+    BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
+    repo.register(mockfunctionResolver);
 
-        repo.compile(mockFunctionName, Arrays.asList(mockExpression), emptyEnv);
-        verify(functionExpressionBuilder, times(1)).apply(any());
-    }
+    repo.compile(mockFunctionName, Arrays.asList(mockExpression), emptyEnv);
+    verify(functionExpressionBuilder, times(1)).apply(any());
+  }
 
-    @Test
-    @DisplayName("resolve registered function should pass")
-    void resolve() {
-        BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
-        when(functionSignature.getFunctionName()).thenReturn(mockFunctionName);
-        when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName);
-        when(mockfunctionResolver.resolve(functionSignature)).thenReturn(functionExpressionBuilder);
-        when(mockMap.containsKey(mockFunctionName)).thenReturn(true);
-        when(mockMap.get(mockFunctionName)).thenReturn(mockfunctionResolver);
-        repo.register(mockfunctionResolver);
+  @Test
+  @DisplayName("resolve registered function should pass")
+  void resolve() {
+    when(functionSignature.getFunctionName()).thenReturn(mockFunctionName);
+    when(mockfunctionResolver.getFunctionName()).thenReturn(mockFunctionName);
+    when(mockfunctionResolver.resolve(functionSignature)).thenReturn(functionExpressionBuilder);
+    when(mockMap.containsKey(mockFunctionName)).thenReturn(true);
+    when(mockMap.get(mockFunctionName)).thenReturn(mockfunctionResolver);
+    BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
+    repo.register(mockfunctionResolver);
 
-        assertEquals(functionExpressionBuilder, repo.resolve(functionSignature));
-    }
+    assertEquals(functionExpressionBuilder, repo.resolve(functionSignature));
+  }
 
-    @Test
-    @DisplayName("resolve unregistered function should throw exception")
-    void resolve_unregistered() {
-        BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
-        when(mockMap.containsKey(any())).thenReturn(false);
-        repo.register(mockfunctionResolver);
+  @Test
+  @DisplayName("resolve unregistered function should throw exception")
+  void resolve_unregistered() {
+    BuiltinFunctionRepository repo = new BuiltinFunctionRepository(mockMap);
+    when(mockMap.containsKey(any())).thenReturn(false);
+    repo.register(mockfunctionResolver);
 
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> repo.resolve(new FunctionSignature(FunctionName.of("unknown"), Arrays.asList())));
-        assertEquals("unsupported function name: unknown", exception.getMessage());
-    }
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> repo.resolve(new FunctionSignature(FunctionName.of("unknown"), Arrays.asList())));
+    assertEquals("unsupported function name: unknown", exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolverTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolverTest.java
index 1ad39af6ed..d0b055334c 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolverTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionResolverTest.java
@@ -15,6 +15,10 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
 import com.google.common.collect.ImmutableMap;
 import org.junit.jupiter.api.DisplayNameGeneration;
@@ -24,63 +28,60 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.Mockito.when;
-
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 @ExtendWith(MockitoExtension.class)
 class FunctionResolverTest {
-    @Mock
-    private FunctionSignature exactlyMatchFS;
-    @Mock
-    private FunctionSignature bestMatchFS;
-    @Mock
-    private FunctionSignature leastMatchFS;
-    @Mock
-    private FunctionSignature notMatchFS;
-    @Mock
-    private FunctionSignature functionSignature;
-    @Mock
-    private FunctionBuilder exactlyMatchBuilder;
-    @Mock
-    private FunctionBuilder bestMatchBuilder;
-    @Mock
-    private FunctionBuilder leastMatchBuilder;
-    @Mock
-    private FunctionBuilder notMatchBuilder;
+  @Mock
+  private FunctionSignature exactlyMatchFS;
+  @Mock
+  private FunctionSignature bestMatchFS;
+  @Mock
+  private FunctionSignature leastMatchFS;
+  @Mock
+  private FunctionSignature notMatchFS;
+  @Mock
+  private FunctionSignature functionSignature;
+  @Mock
+  private FunctionBuilder exactlyMatchBuilder;
+  @Mock
+  private FunctionBuilder bestMatchBuilder;
+  @Mock
+  private FunctionBuilder leastMatchBuilder;
+  @Mock
+  private FunctionBuilder notMatchBuilder;
 
-    private FunctionName functionName = FunctionName.of("add");
+  private FunctionName functionName = FunctionName.of("add");
 
-    @Test
-    void resolve_function_signature_exactly_match() {
-        when(functionSignature.match(exactlyMatchFS)).thenReturn(WideningTypeRule.TYPE_EQUAL);
-        FunctionResolver resolver = new FunctionResolver(functionName,
-                ImmutableMap.of(exactlyMatchFS, exactlyMatchBuilder));
+  @Test
+  void resolve_function_signature_exactly_match() {
+    when(functionSignature.match(exactlyMatchFS)).thenReturn(WideningTypeRule.TYPE_EQUAL);
+    FunctionResolver resolver = new FunctionResolver(functionName,
+        ImmutableMap.of(exactlyMatchFS, exactlyMatchBuilder));
 
-        assertEquals(exactlyMatchBuilder, resolver.resolve(functionSignature));
-    }
+    assertEquals(exactlyMatchBuilder, resolver.resolve(functionSignature));
+  }
 
-    @Test
-    void resolve_function_signature_best_match() {
-        when(functionSignature.match(bestMatchFS)).thenReturn(1);
-        when(functionSignature.match(leastMatchFS)).thenReturn(2);
-        FunctionResolver resolver = new FunctionResolver(functionName,
-                ImmutableMap.of(bestMatchFS, bestMatchBuilder, leastMatchFS, leastMatchBuilder));
+  @Test
+  void resolve_function_signature_best_match() {
+    when(functionSignature.match(bestMatchFS)).thenReturn(1);
+    when(functionSignature.match(leastMatchFS)).thenReturn(2);
+    FunctionResolver resolver = new FunctionResolver(functionName,
+        ImmutableMap.of(bestMatchFS, bestMatchBuilder, leastMatchFS, leastMatchBuilder));
 
-        assertEquals(bestMatchBuilder, resolver.resolve(functionSignature));
-    }
+    assertEquals(bestMatchBuilder, resolver.resolve(functionSignature));
+  }
 
-    @Test
-    void resolve_function_not_match() {
-        when(functionSignature.match(notMatchFS)).thenReturn(WideningTypeRule.IMPOSSIBLE_WIDENING);
-        when(notMatchFS.formatTypes()).thenReturn("[INTEGER,INTEGER]");
-        when(functionSignature.formatTypes()).thenReturn("[BOOLEAN,BOOLEAN]");
-        FunctionResolver resolver = new FunctionResolver(functionName,
-                ImmutableMap.of(notMatchFS, notMatchBuilder));
+  @Test
+  void resolve_function_not_match() {
+    when(functionSignature.match(notMatchFS)).thenReturn(WideningTypeRule.IMPOSSIBLE_WIDENING);
+    when(notMatchFS.formatTypes()).thenReturn("[INTEGER,INTEGER]");
+    when(functionSignature.formatTypes()).thenReturn("[BOOLEAN,BOOLEAN]");
+    FunctionResolver resolver = new FunctionResolver(functionName,
+        ImmutableMap.of(notMatchFS, notMatchBuilder));
 
-        ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
-                () -> resolver.resolve(functionSignature));
-        assertEquals("add function expected {[INTEGER,INTEGER]}, but get [BOOLEAN,BOOLEAN]", exception.getMessage());
-    }
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> resolver.resolve(functionSignature));
+    assertEquals("add function expected {[INTEGER,INTEGER]}, but get [BOOLEAN,BOOLEAN]",
+        exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignatureTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignatureTest.java
index 47436ef46a..ed73a16dc9 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignatureTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/FunctionSignatureTest.java
@@ -15,7 +15,14 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
+import static com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature.EXACTLY_MATCH;
+import static com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature.NOT_MATCH;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import java.util.Arrays;
+import java.util.List;
 import org.junit.jupiter.api.DisplayNameGeneration;
 import org.junit.jupiter.api.DisplayNameGenerator;
 import org.junit.jupiter.api.Test;
@@ -23,74 +30,74 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import java.util.Arrays;
-import java.util.List;
-
-import static com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature.EXACTLY_MATCH;
-import static com.amazon.opendistroforelasticsearch.sql.expression.function.FunctionSignature.NOT_MATCH;
-import static org.junit.jupiter.api.Assertions.*;
-import static org.mockito.Mockito.when;
-
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 @ExtendWith(MockitoExtension.class)
 class FunctionSignatureTest {
-    @Mock
-    private FunctionSignature funcSignature;
-    @Mock
-    private List<ExprType> funcParamTypeList;
-
-    private FunctionName unresolvedFuncName = FunctionName.of("add");
-    private List<ExprType> unresolvedParamTypeList = Arrays.asList(ExprType.INTEGER, ExprType.FLOAT);
-
-    @Test
-    void signature_name_not_match() {
-        when(funcSignature.getFunctionName()).thenReturn(FunctionName.of(("diff")));
-        FunctionSignature unresolvedFunSig = new FunctionSignature(this.unresolvedFuncName, unresolvedParamTypeList);
-
-        assertEquals(NOT_MATCH, unresolvedFunSig.match(funcSignature));
-    }
-
-    @Test
-    void signature_arguments_size_not_match() {
-        when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
-        when(funcSignature.getParamTypeList()).thenReturn(funcParamTypeList);
-        when(funcParamTypeList.size()).thenReturn(1);
-        FunctionSignature unresolvedFunSig = new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
-
-        assertEquals(NOT_MATCH, unresolvedFunSig.match(funcSignature));
-    }
-
-    @Test
-    void signature_exactly_match() {
-        when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
-        when(funcSignature.getParamTypeList()).thenReturn(unresolvedParamTypeList);
-        FunctionSignature unresolvedFunSig = new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
-
-        assertEquals(EXACTLY_MATCH, unresolvedFunSig.match(funcSignature));
-    }
-
-    @Test
-    void signature_not_match() {
-        when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
-        when(funcSignature.getParamTypeList()).thenReturn(Arrays.asList(ExprType.STRING, ExprType.STRING));
-        FunctionSignature unresolvedFunSig = new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
-
-        assertEquals(NOT_MATCH, unresolvedFunSig.match(funcSignature));
-    }
-
-    @Test
-    void signature_widening_match() {
-        when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
-        when(funcSignature.getParamTypeList()).thenReturn(Arrays.asList(ExprType.FLOAT, ExprType.FLOAT));
-        FunctionSignature unresolvedFunSig = new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
-
-        assertEquals(2, unresolvedFunSig.match(funcSignature));
-    }
-
-    @Test
-    void format_types() {
-        FunctionSignature unresolvedFunSig = new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
-
-        assertEquals("[INTEGER,FLOAT]", unresolvedFunSig.formatTypes());
-    }
+  @Mock
+  private FunctionSignature funcSignature;
+  @Mock
+  private List<ExprType> funcParamTypeList;
+
+  private FunctionName unresolvedFuncName = FunctionName.of("add");
+  private List<ExprType> unresolvedParamTypeList = Arrays.asList(ExprType.INTEGER, ExprType.FLOAT);
+
+  @Test
+  void signature_name_not_match() {
+    when(funcSignature.getFunctionName()).thenReturn(FunctionName.of(("diff")));
+    FunctionSignature unresolvedFunSig =
+        new FunctionSignature(this.unresolvedFuncName, unresolvedParamTypeList);
+
+    assertEquals(NOT_MATCH, unresolvedFunSig.match(funcSignature));
+  }
+
+  @Test
+  void signature_arguments_size_not_match() {
+    when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
+    when(funcSignature.getParamTypeList()).thenReturn(funcParamTypeList);
+    when(funcParamTypeList.size()).thenReturn(1);
+    FunctionSignature unresolvedFunSig =
+        new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
+
+    assertEquals(NOT_MATCH, unresolvedFunSig.match(funcSignature));
+  }
+
+  @Test
+  void signature_exactly_match() {
+    when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
+    when(funcSignature.getParamTypeList()).thenReturn(unresolvedParamTypeList);
+    FunctionSignature unresolvedFunSig =
+        new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
+
+    assertEquals(EXACTLY_MATCH, unresolvedFunSig.match(funcSignature));
+  }
+
+  @Test
+  void signature_not_match() {
+    when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
+    when(funcSignature.getParamTypeList())
+        .thenReturn(Arrays.asList(ExprType.STRING, ExprType.STRING));
+    FunctionSignature unresolvedFunSig =
+        new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
+
+    assertEquals(NOT_MATCH, unresolvedFunSig.match(funcSignature));
+  }
+
+  @Test
+  void signature_widening_match() {
+    when(funcSignature.getFunctionName()).thenReturn(unresolvedFuncName);
+    when(funcSignature.getParamTypeList())
+        .thenReturn(Arrays.asList(ExprType.FLOAT, ExprType.FLOAT));
+    FunctionSignature unresolvedFunSig =
+        new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
+
+    assertEquals(2, unresolvedFunSig.match(funcSignature));
+  }
+
+  @Test
+  void format_types() {
+    FunctionSignature unresolvedFunSig =
+        new FunctionSignature(unresolvedFuncName, unresolvedParamTypeList);
+
+    assertEquals("[INTEGER,FLOAT]", unresolvedFunSig.formatTypes());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRuleTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRuleTest.java
index dd0288dca2..81a831fe91 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRuleTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/function/WideningTypeRuleTest.java
@@ -15,20 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.function;
 
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
-import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
-import com.google.common.collect.ImmutableTable;
-import com.google.common.collect.Lists;
-import com.google.common.collect.Table;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
-
-import java.util.Arrays;
-import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.DOUBLE;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.FLOAT;
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprType.INTEGER;
@@ -39,68 +25,84 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
+import com.amazon.opendistroforelasticsearch.sql.exception.ExpressionEvaluationException;
+import com.google.common.collect.ImmutableTable;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Table;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+
 class WideningTypeRuleTest {
-    private static Table<ExprType, ExprType, Integer> numberWidenRule = new ImmutableTable.Builder<ExprType, ExprType,
-            Integer>()
-            .put(INTEGER, LONG, 1)
-            .put(INTEGER, FLOAT, 2)
-            .put(INTEGER, DOUBLE, 3)
-            .put(LONG, FLOAT, 1)
-            .put(LONG, DOUBLE, 2)
-            .put(FLOAT, DOUBLE, 1)
-            .build();
+  private static Table<ExprType, ExprType, Integer> numberWidenRule =
+      new ImmutableTable.Builder<ExprType, ExprType,
+          Integer>()
+          .put(INTEGER, LONG, 1)
+          .put(INTEGER, FLOAT, 2)
+          .put(INTEGER, DOUBLE, 3)
+          .put(LONG, FLOAT, 1)
+          .put(LONG, DOUBLE, 2)
+          .put(FLOAT, DOUBLE, 1)
+          .build();
 
-    private static Stream<Arguments> distanceArguments() {
-        List<ExprType> exprTypes = Arrays.asList(ExprType.values()).stream().filter(type -> type != UNKNOWN).collect(
-                Collectors.toList());
-        return Lists.cartesianProduct(exprTypes, exprTypes).stream()
-                .map(list -> {
-                    ExprType type1 = list.get(0);
-                    ExprType type2 = list.get(1);
-                    if (type1 == type2) {
-                        return Arguments.of(type1, type2, TYPE_EQUAL);
-                    } else if (numberWidenRule.contains(type1, type2)) {
-                        return Arguments.of(type1, type2, numberWidenRule.get(type1, type2));
-                    } else {
-                        return Arguments.of(type1, type2, IMPOSSIBLE_WIDENING);
-                    }
-                });
-    }
+  private static Stream<Arguments> distanceArguments() {
+    List<ExprType> exprTypes =
+        Arrays.asList(ExprType.values()).stream().filter(type -> type != UNKNOWN).collect(
+            Collectors.toList());
+    return Lists.cartesianProduct(exprTypes, exprTypes).stream()
+        .map(list -> {
+          ExprType type1 = list.get(0);
+          ExprType type2 = list.get(1);
+          if (type1 == type2) {
+            return Arguments.of(type1, type2, TYPE_EQUAL);
+          } else if (numberWidenRule.contains(type1, type2)) {
+            return Arguments.of(type1, type2, numberWidenRule.get(type1, type2));
+          } else {
+            return Arguments.of(type1, type2, IMPOSSIBLE_WIDENING);
+          }
+        });
+  }
 
-    private static Stream<Arguments> validMaxTypes() {
-        List<ExprType> exprTypes = Arrays.asList(ExprType.values()).stream().filter(type -> type != UNKNOWN).collect(
-                Collectors.toList());
-        return Lists.cartesianProduct(exprTypes, exprTypes).stream()
-                .map(list -> {
-                    ExprType type1 = list.get(0);
-                    ExprType type2 = list.get(1);
-                    if (type1 == type2) {
-                        return Arguments.of(type1, type2, type1);
-                    } else if (numberWidenRule.contains(type1, type2)) {
-                        return Arguments.of(type1, type2, type2);
-                    } else if (numberWidenRule.contains(type2, type1)){
-                        return Arguments.of(type1, type2, type1);
-                    } else {
-                        return Arguments.of(type1, type2, null);
-                    }
-                });
-    }
+  private static Stream<Arguments> validMaxTypes() {
+    List<ExprType> exprTypes =
+        Arrays.asList(ExprType.values()).stream().filter(type -> type != UNKNOWN).collect(
+            Collectors.toList());
+    return Lists.cartesianProduct(exprTypes, exprTypes).stream()
+        .map(list -> {
+          ExprType type1 = list.get(0);
+          ExprType type2 = list.get(1);
+          if (type1 == type2) {
+            return Arguments.of(type1, type2, type1);
+          } else if (numberWidenRule.contains(type1, type2)) {
+            return Arguments.of(type1, type2, type2);
+          } else if (numberWidenRule.contains(type2, type1)) {
+            return Arguments.of(type1, type2, type1);
+          } else {
+            return Arguments.of(type1, type2, null);
+          }
+        });
+  }
 
-    @ParameterizedTest
-    @MethodSource("distanceArguments")
-    public void distance(ExprType v1, ExprType v2, Integer expected) {
-        assertEquals(expected, WideningTypeRule.distance(v1, v2));
-    }
+  @ParameterizedTest
+  @MethodSource("distanceArguments")
+  public void distance(ExprType v1, ExprType v2, Integer expected) {
+    assertEquals(expected, WideningTypeRule.distance(v1, v2));
+  }
 
-    @ParameterizedTest
-    @MethodSource("validMaxTypes")
-    public void max(ExprType v1, ExprType v2, ExprType expected) {
-        if (null == expected) {
-            ExpressionEvaluationException exception = assertThrows(
-                    ExpressionEvaluationException.class, () -> WideningTypeRule.max(v1, v2));
-            assertEquals(String.format("no max type of %s and %s ", v1, v2),exception.getMessage());
-        } else {
-            assertEquals(expected, WideningTypeRule.max(v1, v2));
-        }
+  @ParameterizedTest
+  @MethodSource("validMaxTypes")
+  public void max(ExprType v1, ExprType v2, ExprType expected) {
+    if (null == expected) {
+      ExpressionEvaluationException exception = assertThrows(
+          ExpressionEvaluationException.class, () -> WideningTypeRule.max(v1, v2));
+      assertEquals(String.format("no max type of %s and %s ", v1, v2), exception.getMessage());
+    } else {
+      assertEquals(expected, WideningTypeRule.max(v1, v2));
     }
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunctionTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunctionTest.java
index 863086d205..07633f0a7f 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunctionTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/ArithmeticFunctionTest.java
@@ -15,6 +15,14 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.scalar.arthmetic;
 
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_MISSING_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_NULL_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
+import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.literal;
+import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.ref;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
@@ -26,244 +34,242 @@
 import com.amazon.opendistroforelasticsearch.sql.expression.function.BuiltinFunctionName;
 import com.amazon.opendistroforelasticsearch.sql.expression.function.WideningTypeRule;
 import com.google.common.collect.Lists;
-import org.junit.jupiter.api.DisplayNameGeneration;
-import org.junit.jupiter.api.DisplayNameGenerator;
-import org.junit.jupiter.params.ParameterizedTest;
-import org.junit.jupiter.params.provider.Arguments;
-import org.junit.jupiter.params.provider.MethodSource;
-
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.BiFunction;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_MISSING_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.INT_TYPE_NULL_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.integerValue;
-import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.literal;
-import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.ref;
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.junit.jupiter.api.DisplayNameGeneration;
+import org.junit.jupiter.api.DisplayNameGenerator;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
 
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 class ArithmeticFunctionTest extends ExpressionTestBase {
 
-    private static Stream<Arguments> arithmeticFunctionArguments() {
-        List<ExprValue> numberOp1 = Stream.of(3, 3L, 3f, 3D)
-                .map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
-        List<ExprValue> numberOp2 = Stream.of(2, 2L, 2f, 2D)
-                .map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
-        return Lists.cartesianProduct(numberOp1, numberOp2).stream()
-                .map(list -> Arguments.of(list.get(0), list.get(1)));
-    }
+  private static Stream<Arguments> arithmeticFunctionArguments() {
+    List<ExprValue> numberOp1 = Stream.of(3, 3L, 3f, 3D)
+        .map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
+    List<ExprValue> numberOp2 = Stream.of(2, 2L, 2f, 2D)
+        .map(ExprValueUtils::fromObjectValue).collect(Collectors.toList());
+    return Lists.cartesianProduct(numberOp1, numberOp2).stream()
+        .map(list -> Arguments.of(list.get(0), list.get(1)));
+  }
 
-    private static Stream<Arguments> arithmeticOperatorArguments() {
-        return Stream.of(BuiltinFunctionName.ADD, BuiltinFunctionName.SUBTRACT, BuiltinFunctionName.MULTIPLY,
-                BuiltinFunctionName.DIVIDE, BuiltinFunctionName.DIVIDE).map(Arguments::of);
-    }
+  private static Stream<Arguments> arithmeticOperatorArguments() {
+    return Stream
+        .of(BuiltinFunctionName.ADD, BuiltinFunctionName.SUBTRACT, BuiltinFunctionName.MULTIPLY,
+            BuiltinFunctionName.DIVIDE, BuiltinFunctionName.DIVIDE).map(Arguments::of);
+  }
 
-    @ParameterizedTest(name = "add({1}, {2})")
-    @MethodSource("arithmeticFunctionArguments")
-    public void add(ExprValue op1, ExprValue op2) {
-        FunctionExpression expression = dsl.add(typeEnv(), literal(op1), literal(op2));
-        ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
-        assertEquals(expectedType, expression.type(null));
-        assertValueEqual(BuiltinFunctionName.ADD, expectedType, op1, op2, expression.valueOf(null));
-    }
+  @ParameterizedTest(name = "add({1}, {2})")
+  @MethodSource("arithmeticFunctionArguments")
+  public void add(ExprValue op1, ExprValue op2) {
+    FunctionExpression expression = dsl.add(typeEnv(), literal(op1), literal(op2));
+    ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
+    assertEquals(expectedType, expression.type(null));
+    assertValueEqual(BuiltinFunctionName.ADD, expectedType, op1, op2, expression.valueOf(null));
+  }
 
-    @ParameterizedTest(name = "{0}(int,null)")
-    @MethodSource("arithmeticOperatorArguments")
-    public void arithmetic_int_null(BuiltinFunctionName builtinFunctionName) {
-        BiFunction<Environment<Expression, ExprType>,
-                List<Expression>, FunctionExpression> function = functionMapping(builtinFunctionName);
+  @ParameterizedTest(name = "{0}(int,null)")
+  @MethodSource("arithmeticOperatorArguments")
+  public void arithmetic_int_null(BuiltinFunctionName builtinFunctionName) {
+    BiFunction<Environment<Expression, ExprType>,
+        List<Expression>, FunctionExpression> function = functionMapping(builtinFunctionName);
 
-        FunctionExpression functionExpression = function.apply(typeEnv(), Arrays.asList(literal(integerValue(1)),
-                ref(INT_TYPE_NULL_VALUE_FIELD)));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_NULL, functionExpression.valueOf(valueEnv()));
+    FunctionExpression functionExpression =
+        function.apply(typeEnv(), Arrays.asList(literal(integerValue(1)),
+            ref(INT_TYPE_NULL_VALUE_FIELD)));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_NULL, functionExpression.valueOf(valueEnv()));
 
-        functionExpression = function.apply(typeEnv(),
-                Arrays.asList(ref(INT_TYPE_NULL_VALUE_FIELD), literal(integerValue(1))));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_NULL, functionExpression.valueOf(valueEnv()));
-    }
+    functionExpression = function.apply(typeEnv(),
+        Arrays.asList(ref(INT_TYPE_NULL_VALUE_FIELD), literal(integerValue(1))));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_NULL, functionExpression.valueOf(valueEnv()));
+  }
 
-    @ParameterizedTest(name = "{0}(int,missing)")
-    @MethodSource("arithmeticOperatorArguments")
-    public void arithmetic_int_missing(BuiltinFunctionName builtinFunctionName) {
-        BiFunction<Environment<Expression, ExprType>,
-                List<Expression>, FunctionExpression> function = functionMapping(builtinFunctionName);
-        FunctionExpression functionExpression = function.apply(typeEnv(), Arrays.asList(literal(integerValue(1)),
-                ref(INT_TYPE_MISSING_VALUE_FIELD)));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
+  @ParameterizedTest(name = "{0}(int,missing)")
+  @MethodSource("arithmeticOperatorArguments")
+  public void arithmetic_int_missing(BuiltinFunctionName builtinFunctionName) {
+    BiFunction<Environment<Expression, ExprType>,
+        List<Expression>, FunctionExpression> function = functionMapping(builtinFunctionName);
+    FunctionExpression functionExpression =
+        function.apply(typeEnv(), Arrays.asList(literal(integerValue(1)),
+            ref(INT_TYPE_MISSING_VALUE_FIELD)));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
 
-        functionExpression = function.apply(typeEnv(), Arrays.asList(ref(INT_TYPE_MISSING_VALUE_FIELD),
-                literal(integerValue(1))));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
-    }
+    functionExpression = function.apply(typeEnv(), Arrays.asList(ref(INT_TYPE_MISSING_VALUE_FIELD),
+        literal(integerValue(1))));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
+  }
 
-    @ParameterizedTest(name = "{0}(null,missing)")
-    @MethodSource("arithmeticOperatorArguments")
-    public void arithmetic_null_missing(BuiltinFunctionName builtinFunctionName) {
-        BiFunction<Environment<Expression, ExprType>,
-                List<Expression>, FunctionExpression> function = functionMapping(builtinFunctionName);
-        FunctionExpression functionExpression = function.apply(typeEnv(),
-                Arrays.asList(ref(INT_TYPE_NULL_VALUE_FIELD), ref(INT_TYPE_NULL_VALUE_FIELD)));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_NULL, functionExpression.valueOf(valueEnv()));
+  @ParameterizedTest(name = "{0}(null,missing)")
+  @MethodSource("arithmeticOperatorArguments")
+  public void arithmetic_null_missing(BuiltinFunctionName builtinFunctionName) {
+    BiFunction<Environment<Expression, ExprType>,
+        List<Expression>, FunctionExpression> function = functionMapping(builtinFunctionName);
+    FunctionExpression functionExpression = function.apply(typeEnv(),
+        Arrays.asList(ref(INT_TYPE_NULL_VALUE_FIELD), ref(INT_TYPE_NULL_VALUE_FIELD)));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_NULL, functionExpression.valueOf(valueEnv()));
 
-        functionExpression = function.apply(typeEnv(),
-                Arrays.asList(ref(INT_TYPE_MISSING_VALUE_FIELD), ref(INT_TYPE_MISSING_VALUE_FIELD)));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
+    functionExpression = function.apply(typeEnv(),
+        Arrays.asList(ref(INT_TYPE_MISSING_VALUE_FIELD), ref(INT_TYPE_MISSING_VALUE_FIELD)));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
 
-        functionExpression = function.apply(typeEnv(),
-                Arrays.asList(ref(INT_TYPE_MISSING_VALUE_FIELD), ref(INT_TYPE_NULL_VALUE_FIELD)));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
+    functionExpression = function.apply(typeEnv(),
+        Arrays.asList(ref(INT_TYPE_MISSING_VALUE_FIELD), ref(INT_TYPE_NULL_VALUE_FIELD)));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
 
-        functionExpression = function.apply(typeEnv(),
-                Arrays.asList(ref(INT_TYPE_NULL_VALUE_FIELD), ref(INT_TYPE_MISSING_VALUE_FIELD)));
-        assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
-    }
+    functionExpression = function.apply(typeEnv(),
+        Arrays.asList(ref(INT_TYPE_NULL_VALUE_FIELD), ref(INT_TYPE_MISSING_VALUE_FIELD)));
+    assertEquals(ExprType.INTEGER, functionExpression.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, functionExpression.valueOf(valueEnv()));
+  }
 
-    @ParameterizedTest(name = "subtract({1}, {2})")
-    @MethodSource("arithmeticFunctionArguments")
-    public void subtract(ExprValue op1, ExprValue op2) {
-        FunctionExpression expression = dsl.subtract(typeEnv(), literal(op1), literal(op2));
-        ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
-        assertEquals(expectedType, expression.type(null));
-        assertValueEqual(BuiltinFunctionName.SUBTRACT, expectedType, op1, op2, expression.valueOf(null));
-    }
+  @ParameterizedTest(name = "subtract({1}, {2})")
+  @MethodSource("arithmeticFunctionArguments")
+  public void subtract(ExprValue op1, ExprValue op2) {
+    FunctionExpression expression = dsl.subtract(typeEnv(), literal(op1), literal(op2));
+    ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
+    assertEquals(expectedType, expression.type(null));
+    assertValueEqual(BuiltinFunctionName.SUBTRACT, expectedType, op1, op2,
+        expression.valueOf(null));
+  }
 
-    @ParameterizedTest(name = "multiply({1}, {2})")
-    @MethodSource("arithmeticFunctionArguments")
-    public void multiply(ExprValue op1, ExprValue op2) {
-        FunctionExpression expression = dsl.multiply(typeEnv(), literal(op1), literal(op2));
-        ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
-        assertEquals(expectedType, expression.type(null));
-        assertValueEqual(BuiltinFunctionName.MULTIPLY, expectedType, op1, op2, expression.valueOf(null));
-    }
+  @ParameterizedTest(name = "multiply({1}, {2})")
+  @MethodSource("arithmeticFunctionArguments")
+  public void multiply(ExprValue op1, ExprValue op2) {
+    FunctionExpression expression = dsl.multiply(typeEnv(), literal(op1), literal(op2));
+    ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
+    assertEquals(expectedType, expression.type(null));
+    assertValueEqual(BuiltinFunctionName.MULTIPLY, expectedType, op1, op2,
+        expression.valueOf(null));
+  }
 
-    @ParameterizedTest(name = "divide({1}, {2})")
-    @MethodSource("arithmeticFunctionArguments")
-    public void divide(ExprValue op1, ExprValue op2) {
-        FunctionExpression expression = dsl.divide(typeEnv(), literal(op1), literal(op2));
-        ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
-        assertEquals(expectedType, expression.type(null));
-        assertValueEqual(BuiltinFunctionName.DIVIDE, expectedType, op1, op2, expression.valueOf(null));
-    }
+  @ParameterizedTest(name = "divide({1}, {2})")
+  @MethodSource("arithmeticFunctionArguments")
+  public void divide(ExprValue op1, ExprValue op2) {
+    FunctionExpression expression = dsl.divide(typeEnv(), literal(op1), literal(op2));
+    ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
+    assertEquals(expectedType, expression.type(null));
+    assertValueEqual(BuiltinFunctionName.DIVIDE, expectedType, op1, op2, expression.valueOf(null));
+  }
 
-    @ParameterizedTest(name = "module({1}, {2})")
-    @MethodSource("arithmeticFunctionArguments")
-    public void module(ExprValue op1, ExprValue op2) {
-        FunctionExpression expression = dsl.module(typeEnv(), literal(op1), literal(op2));
-        ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
-        assertEquals(expectedType, expression.type(null));
-        assertValueEqual(BuiltinFunctionName.MODULES, expectedType, op1, op2, expression.valueOf(null));
-    }
+  @ParameterizedTest(name = "module({1}, {2})")
+  @MethodSource("arithmeticFunctionArguments")
+  public void module(ExprValue op1, ExprValue op2) {
+    FunctionExpression expression = dsl.module(typeEnv(), literal(op1), literal(op2));
+    ExprType expectedType = WideningTypeRule.max(op1.type(), op2.type());
+    assertEquals(expectedType, expression.type(null));
+    assertValueEqual(BuiltinFunctionName.MODULES, expectedType, op1, op2, expression.valueOf(null));
+  }
 
-    protected void assertValueEqual(BuiltinFunctionName builtinFunctionName, ExprType type, ExprValue op1,
-                                    ExprValue op2,
-                                    ExprValue actual) {
-        switch (type) {
-            case INTEGER:
-                Integer vi1 = ExprValueUtils.getIntegerValue(op1);
-                Integer vi2 = ExprValueUtils.getIntegerValue(op2);
-                Integer viActual = ExprValueUtils.getIntegerValue(actual);
-                switch (builtinFunctionName) {
-                    case ADD:
-                        assertEquals(vi1 + vi2, viActual);
-                        return;
-                    case SUBTRACT:
-                        assertEquals(vi1 - vi2, viActual);
-                        return;
-                    case DIVIDE:
-                        assertEquals(vi1 / vi2, viActual);
-                        return;
-                    case MULTIPLY:
-                        assertEquals(vi1 * vi2, viActual);
-                        return;
-                    case MODULES:
-                        assertEquals(vi1 % vi2, viActual);
-                        return;
-                    default:
-                        throw new IllegalStateException("illegal function name " + builtinFunctionName);
-                }
-            case LONG:
-                Long vl1 = ExprValueUtils.getLongValue(op1);
-                Long vl2 = ExprValueUtils.getLongValue(op2);
-                Long vlActual = ExprValueUtils.getLongValue(actual);
-                switch (builtinFunctionName) {
-                    case ADD:
-                        assertEquals(vl1 + vl2, vlActual);
-                        return;
-                    case SUBTRACT:
-                        assertEquals(vl1 - vl2, vlActual);
-                        return;
-                    case DIVIDE:
-                        assertEquals(vl1 / vl2, vlActual);
-                        return;
-                    case MULTIPLY:
-                        assertEquals(vl1 * vl2, vlActual);
-                        return;
-                    case MODULES:
-                        assertEquals(vl1 % vl2, vlActual);
-                        return;
-                    default:
-                        throw new IllegalStateException("illegal function name " + builtinFunctionName);
-                }
-            case FLOAT:
-                Float vf1 = ExprValueUtils.getFloatValue(op1);
-                Float vf2 = ExprValueUtils.getFloatValue(op2);
-                Float vfActual = ExprValueUtils.getFloatValue(actual);
-                switch (builtinFunctionName) {
-                    case ADD:
-                        assertEquals(vf1 + vf2, vfActual);
-                        return;
-                    case SUBTRACT:
-                        assertEquals(vf1 - vf2, vfActual);
-                        return;
-                    case DIVIDE:
-                        assertEquals(vf1 / vf2, vfActual);
-                        return;
-                    case MULTIPLY:
-                        assertEquals(vf1 * vf2, vfActual);
-                        return;
-                    case MODULES:
-                        assertEquals(vf1 % vf2, vfActual);
-                        return;
-                    default:
-                        throw new IllegalStateException("illegal function name " + builtinFunctionName);
-                }
-            case DOUBLE:
-                Double vd1 = ExprValueUtils.getDoubleValue(op1);
-                Double vd2 = ExprValueUtils.getDoubleValue(op2);
-                Double vdActual = ExprValueUtils.getDoubleValue(actual);
-                switch (builtinFunctionName) {
-                    case ADD:
-                        assertEquals(vd1 + vd2, vdActual);
-                        return;
-                    case SUBTRACT:
-                        assertEquals(vd1 - vd2, vdActual);
-                        return;
-                    case DIVIDE:
-                        assertEquals(vd1 / vd2, vdActual);
-                        return;
-                    case MULTIPLY:
-                        assertEquals(vd1 * vd2, vdActual);
-                        return;
-                    case MODULES:
-                        assertEquals(vd1 % vd2, vdActual);
-                        return;
-                    default:
-                        throw new IllegalStateException("illegal function name " + builtinFunctionName);
-                }
+  protected void assertValueEqual(BuiltinFunctionName builtinFunctionName, ExprType type,
+                                  ExprValue op1,
+                                  ExprValue op2,
+                                  ExprValue actual) {
+    switch (type) {
+      case INTEGER:
+        Integer vi1 = ExprValueUtils.getIntegerValue(op1);
+        Integer vi2 = ExprValueUtils.getIntegerValue(op2);
+        Integer viActual = ExprValueUtils.getIntegerValue(actual);
+        switch (builtinFunctionName) {
+          case ADD:
+            assertEquals(vi1 + vi2, viActual);
+            return;
+          case SUBTRACT:
+            assertEquals(vi1 - vi2, viActual);
+            return;
+          case DIVIDE:
+            assertEquals(vi1 / vi2, viActual);
+            return;
+          case MULTIPLY:
+            assertEquals(vi1 * vi2, viActual);
+            return;
+          case MODULES:
+            assertEquals(vi1 % vi2, viActual);
+            return;
+          default:
+            throw new IllegalStateException("illegal function name " + builtinFunctionName);
+        }
+      case LONG:
+        Long vl1 = ExprValueUtils.getLongValue(op1);
+        Long vl2 = ExprValueUtils.getLongValue(op2);
+        Long vlActual = ExprValueUtils.getLongValue(actual);
+        switch (builtinFunctionName) {
+          case ADD:
+            assertEquals(vl1 + vl2, vlActual);
+            return;
+          case SUBTRACT:
+            assertEquals(vl1 - vl2, vlActual);
+            return;
+          case DIVIDE:
+            assertEquals(vl1 / vl2, vlActual);
+            return;
+          case MULTIPLY:
+            assertEquals(vl1 * vl2, vlActual);
+            return;
+          case MODULES:
+            assertEquals(vl1 % vl2, vlActual);
+            return;
+          default:
+            throw new IllegalStateException("illegal function name " + builtinFunctionName);
+        }
+      case FLOAT:
+        Float vf1 = ExprValueUtils.getFloatValue(op1);
+        Float vf2 = ExprValueUtils.getFloatValue(op2);
+        Float vfActual = ExprValueUtils.getFloatValue(actual);
+        switch (builtinFunctionName) {
+          case ADD:
+            assertEquals(vf1 + vf2, vfActual);
+            return;
+          case SUBTRACT:
+            assertEquals(vf1 - vf2, vfActual);
+            return;
+          case DIVIDE:
+            assertEquals(vf1 / vf2, vfActual);
+            return;
+          case MULTIPLY:
+            assertEquals(vf1 * vf2, vfActual);
+            return;
+          case MODULES:
+            assertEquals(vf1 % vf2, vfActual);
+            return;
+          default:
+            throw new IllegalStateException("illegal function name " + builtinFunctionName);
+        }
+      case DOUBLE:
+        Double vd1 = ExprValueUtils.getDoubleValue(op1);
+        Double vd2 = ExprValueUtils.getDoubleValue(op2);
+        Double vdActual = ExprValueUtils.getDoubleValue(actual);
+        switch (builtinFunctionName) {
+          case ADD:
+            assertEquals(vd1 + vd2, vdActual);
+            return;
+          case SUBTRACT:
+            assertEquals(vd1 - vd2, vdActual);
+            return;
+          case DIVIDE:
+            assertEquals(vd1 / vd2, vdActual);
+            return;
+          case MULTIPLY:
+            assertEquals(vd1 * vd2, vdActual);
+            return;
+          case MODULES:
+            assertEquals(vd1 % vd2, vdActual);
+            return;
+          default:
+            throw new IllegalStateException("illegal function name " + builtinFunctionName);
         }
+      default:
+        throw new IllegalStateException("illegal function name " + builtinFunctionName);
     }
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/UnaryFunctionTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/UnaryFunctionTest.java
index 2f7e8e49a1..5984ac5feb 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/UnaryFunctionTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/arthmetic/UnaryFunctionTest.java
@@ -35,6 +35,9 @@
 @DisplayNameGeneration(DisplayNameGenerator.ReplaceUnderscores.class)
 public class UnaryFunctionTest extends ExpressionTestBase {
 
+  /**
+   * Test abs with integer value.
+   */
   @ParameterizedTest(name = "abs({0})")
   @ValueSource(ints = {-2, 2})
   public void abs_int_value(Integer value) {
@@ -43,6 +46,9 @@ public void abs_int_value(Integer value) {
         allOf(hasType(ExprType.INTEGER), hasValue(Math.abs(value))));
   }
 
+  /**
+   * Test abs with long value.
+   */
   @ParameterizedTest(name = "abs({0})")
   @ValueSource(longs = {-2L, 2L})
   public void abs_long_value(Long value) {
@@ -51,6 +57,9 @@ public void abs_long_value(Long value) {
         allOf(hasType(ExprType.LONG), hasValue(Math.abs(value))));
   }
 
+  /**
+   * Test abs with float value.
+   */
   @ParameterizedTest(name = "abs({0})")
   @ValueSource(floats = {-2f, 2f})
   public void abs_float_value(Float value) {
@@ -59,6 +68,9 @@ public void abs_float_value(Float value) {
         allOf(hasType(ExprType.FLOAT), hasValue(Math.abs(value))));
   }
 
+  /**
+   * Test abs with double value.
+   */
   @ParameterizedTest(name = "abs({0})")
   @ValueSource(doubles = {-2L, 2L})
   public void abs_double_value(Double value) {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunctionTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunctionTest.java
index b300511991..f81c6c6e8c 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunctionTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/BinaryPredicateFunctionTest.java
@@ -15,6 +15,16 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate;
 
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_MISSING_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_FALSE;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.fromObjectValue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
@@ -24,283 +34,294 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Lists;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Stream;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.Arguments;
 import org.junit.jupiter.params.provider.MethodSource;
 
-import java.util.Arrays;
-import java.util.List;
-import java.util.stream.Stream;
-
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_MISSING_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_FALSE;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_TRUE;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.fromObjectValue;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 class BinaryPredicateFunctionTest extends ExpressionTestBase {
 
-    private static Stream<Arguments> binaryPredicateArguments() {
-        List<Boolean> booleans = Arrays.asList(true, false);
-        return Lists.cartesianProduct(booleans, booleans).stream()
-                .map(list -> Arguments.of(list.get(0), list.get(1)));
-    }
-
-    private static Stream<Arguments> testEqualArguments() {
-        List<Object> arguments = Arrays.asList(1, 1L, 1F, 1D, "str", true, ImmutableList.of(1),
-                ImmutableMap.of("str", 1));
-        Stream.Builder<Arguments> builder = Stream.builder();
-        for (Object argument : arguments) {
-            builder.add(Arguments.of(fromObjectValue(argument), fromObjectValue(argument)));
-        }
-        return builder.build();
-    }
-
-    @ParameterizedTest(name = "and({0}, {1})")
-    @MethodSource("binaryPredicateArguments")
-    public void test_and(Boolean v1, Boolean v2) {
-        FunctionExpression and = dsl.and(typeEnv(), DSL.literal(booleanValue(v1)), DSL.literal(booleanValue(v2)));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(v1 && v2, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
-    }
-
-    @Test
-    public void test_boolean_and_null() {
-        FunctionExpression and = dsl.and(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
-    }
-
-    @Test
-    public void test_boolean_and_missing() {
-        FunctionExpression and = dsl.and(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
-    }
-
-    @Test
-    public void test_null_and_missing() {
-        FunctionExpression and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
-                DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
-
-        and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
-    }
-
-    @ParameterizedTest(name = "or({0}, {1})")
-    @MethodSource("binaryPredicateArguments")
-    public void test_or(Boolean v1, Boolean v2) {
-        FunctionExpression and = dsl.or(typeEnv(), DSL.literal(booleanValue(v1)), DSL.literal(booleanValue(v2)));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(v1 || v2, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
-    }
-
-    @Test
-    public void test_boolean_or_null() {
-        FunctionExpression or = dsl.or(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
-    }
-
-    @Test
-    public void test_boolean_or_missing() {
-        FunctionExpression or = dsl.or(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, or.valueOf(valueEnv()));
-    }
-
-    @Test
-    public void test_null_or_missing() {
-        FunctionExpression or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
-                DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
-
-        or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
-        assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
-    }
-
-
-    @ParameterizedTest(name = "xor({0}, {1})")
-    @MethodSource("binaryPredicateArguments")
-    public void test_xor(Boolean v1, Boolean v2) {
-        FunctionExpression and = dsl.xor(typeEnv(), DSL.literal(booleanValue(v1)), DSL.literal(booleanValue(v2)));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(v1 ^ v2, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
-    }
-
-    @Test
-    public void test_boolean_xor_null() {
-        FunctionExpression xor = dsl.xor(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
-    }
-
-    @Test
-    public void test_boolean_xor_missing() {
-        FunctionExpression xor = dsl.xor(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, xor.valueOf(valueEnv()));
-    }
-
-    @Test
-    public void test_null_xor_missing() {
-        FunctionExpression xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
-                DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
-
-        xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
-        assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
-    }
-
-    @ParameterizedTest(name = "equal({0}, {1})")
-    @MethodSource("testEqualArguments")
-    public void test_equal(ExprValue v1, ExprValue v2) {
-        FunctionExpression equal = dsl.equal(typeEnv(), DSL.literal(v1), DSL.literal(v2));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(v1.value().equals(v2.value()), ExprValueUtils.getBooleanValue(equal.valueOf(valueEnv())));
-    }
-
-    @Test
-    public void test_null_equal_missing() {
-        FunctionExpression equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
-                DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_TRUE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
-
-        equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
-        assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
-        assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+  private static Stream<Arguments> binaryPredicateArguments() {
+    List<Boolean> booleans = Arrays.asList(true, false);
+    return Lists.cartesianProduct(booleans, booleans).stream()
+        .map(list -> Arguments.of(list.get(0), list.get(1)));
+  }
+
+  private static Stream<Arguments> testEqualArguments() {
+    List<Object> arguments = Arrays.asList(1, 1L, 1F, 1D, "str", true, ImmutableList.of(1),
+        ImmutableMap.of("str", 1));
+    Stream.Builder<Arguments> builder = Stream.builder();
+    for (Object argument : arguments) {
+      builder.add(Arguments.of(fromObjectValue(argument), fromObjectValue(argument)));
     }
+    return builder.build();
+  }
+
+  @ParameterizedTest(name = "and({0}, {1})")
+  @MethodSource("binaryPredicateArguments")
+  public void test_and(Boolean v1, Boolean v2) {
+    FunctionExpression and =
+        dsl.and(typeEnv(), DSL.literal(booleanValue(v1)), DSL.literal(booleanValue(v2)));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(v1 && v2, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
+  }
+
+  @Test
+  public void test_boolean_and_null() {
+    FunctionExpression and =
+        dsl.and(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
+  }
+
+  @Test
+  public void test_boolean_and_missing() {
+    FunctionExpression and =
+        dsl.and(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, and.valueOf(valueEnv()));
+  }
+
+  @Test
+  public void test_null_and_missing() {
+    FunctionExpression and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
+
+    and = dsl.and(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
+  }
+
+  @ParameterizedTest(name = "or({0}, {1})")
+  @MethodSource("binaryPredicateArguments")
+  public void test_or(Boolean v1, Boolean v2) {
+    FunctionExpression and =
+        dsl.or(typeEnv(), DSL.literal(booleanValue(v1)), DSL.literal(booleanValue(v2)));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(v1 || v2, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
+  }
+
+  @Test
+  public void test_boolean_or_null() {
+    FunctionExpression or =
+        dsl.or(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
+  }
+
+  @Test
+  public void test_boolean_or_missing() {
+    FunctionExpression or =
+        dsl.or(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, or.valueOf(valueEnv()));
+  }
+
+  @Test
+  public void test_null_or_missing() {
+    FunctionExpression or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, or.valueOf(valueEnv()));
+
+    or =
+        dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
+
+    or = dsl.or(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, or.type(typeEnv()));
+    assertEquals(LITERAL_NULL, or.valueOf(valueEnv()));
+  }
+
+
+  @ParameterizedTest(name = "xor({0}, {1})")
+  @MethodSource("binaryPredicateArguments")
+  public void test_xor(Boolean v1, Boolean v2) {
+    FunctionExpression and =
+        dsl.xor(typeEnv(), DSL.literal(booleanValue(v1)), DSL.literal(booleanValue(v2)));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(v1 ^ v2, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
+  }
+
+  @Test
+  public void test_boolean_xor_null() {
+    FunctionExpression xor =
+        dsl.xor(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
+  }
+
+  @Test
+  public void test_boolean_xor_missing() {
+    FunctionExpression xor =
+        dsl.xor(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.literal(LITERAL_FALSE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_FALSE));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, xor.valueOf(valueEnv()));
+  }
+
+  @Test
+  public void test_null_xor_missing() {
+    FunctionExpression xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
+
+    xor = dsl.xor(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, xor.type(typeEnv()));
+    assertEquals(LITERAL_NULL, xor.valueOf(valueEnv()));
+  }
+
+  @ParameterizedTest(name = "equal({0}, {1})")
+  @MethodSource("testEqualArguments")
+  public void test_equal(ExprValue v1, ExprValue v2) {
+    FunctionExpression equal = dsl.equal(typeEnv(), DSL.literal(v1), DSL.literal(v2));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(v1.value().equals(v2.value()),
+        ExprValueUtils.getBooleanValue(equal.valueOf(valueEnv())));
+  }
+
+  @Test
+  public void test_null_equal_missing() {
+    FunctionExpression equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_TRUE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD),
+        DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.literal(LITERAL_TRUE), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+
+    equal = dsl.equal(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD), DSL.literal(LITERAL_TRUE));
+    assertEquals(ExprType.BOOLEAN, equal.type(typeEnv()));
+    assertEquals(LITERAL_FALSE, equal.valueOf(valueEnv()));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunctionTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunctionTest.java
index bfebc16d89..a6c308a5aa 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunctionTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/expression/scalar/predicate/UnaryPredicateFunctionTest.java
@@ -15,6 +15,13 @@
 
 package com.amazon.opendistroforelasticsearch.sql.expression.scalar.predicate;
 
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_MISSING_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
+import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
 import com.amazon.opendistroforelasticsearch.sql.expression.DSL;
@@ -24,33 +31,26 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_MISSING_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.config.TestConfig.BOOL_TYPE_NULL_VALUE_FIELD;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_MISSING;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.LITERAL_NULL;
-import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.booleanValue;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 class UnaryPredicateFunctionTest extends ExpressionTestBase {
-    @ParameterizedTest(name = "not({0})")
-    @ValueSource(booleans = {true, false})
-    public void test_not(Boolean v) {
-        FunctionExpression and = dsl.not(typeEnv(), DSL.literal(booleanValue(v)));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(!v, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
-    }
+  @ParameterizedTest(name = "not({0})")
+  @ValueSource(booleans = {true, false})
+  public void test_not(Boolean v) {
+    FunctionExpression and = dsl.not(typeEnv(), DSL.literal(booleanValue(v)));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(!v, ExprValueUtils.getBooleanValue(and.valueOf(valueEnv())));
+  }
 
-    @Test
-    public void test_not_null() {
-        FunctionExpression and = dsl.not(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
-    }
+  @Test
+  public void test_not_null() {
+    FunctionExpression and = dsl.not(typeEnv(), DSL.ref(BOOL_TYPE_NULL_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_NULL, and.valueOf(valueEnv()));
+  }
 
-    @Test
-    public void test_not_missing() {
-        FunctionExpression and = dsl.not(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
-        assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
-        assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
-    }
+  @Test
+  public void test_not_missing() {
+    FunctionExpression and = dsl.not(typeEnv(), DSL.ref(BOOL_TYPE_MISSING_VALUE_FIELD));
+    assertEquals(ExprType.BOOLEAN, and.type(typeEnv()));
+    assertEquals(LITERAL_MISSING, and.valueOf(valueEnv()));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/PlannerTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/PlannerTest.java
index 9b7954bf1d..a9b4a54e39 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/PlannerTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/PlannerTest.java
@@ -15,6 +15,10 @@
 
 package com.amazon.opendistroforelasticsearch.sql.planner;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.expression.DSL;
 import com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalAggregation;
@@ -34,100 +38,95 @@
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import java.util.Map;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import java.util.Map;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 public class PlannerTest extends PhysicalPlanTestBase {
-    @Mock
-    private PhysicalPlan scan;
-
-    @Mock
-    private StorageEngine storageEngine;
+  @Mock
+  private PhysicalPlan scan;
+
+  @Mock
+  private StorageEngine storageEngine;
+
+  @BeforeEach
+  public void setUp() {
+    when(storageEngine.getTable(any())).thenReturn(new MockTable());
+  }
+
+  @Test
+  public void planner_test() {
+    assertPhysicalPlan(
+        PhysicalPlanDSL.rename(
+            PhysicalPlanDSL.agg(
+                PhysicalPlanDSL.filter(
+                    scan,
+                    dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(10))
+                ),
+                ImmutableList.of(dsl.avg(typeEnv(), DSL.ref("response"))),
+                ImmutableList.of()
+            ),
+            ImmutableMap.of(DSL.ref("ivalue"), DSL.ref("avg(response)"))
+        ),
+        LogicalPlanDSL.rename(
+            LogicalPlanDSL.aggregation(
+                LogicalPlanDSL.filter(
+                    LogicalPlanDSL.relation("schema"),
+                    dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(10))
+                ),
+                ImmutableList.of(dsl.avg(typeEnv(), DSL.ref("response"))),
+                ImmutableList.of()
+            ),
+            ImmutableMap.of(DSL.ref("ivalue"), DSL.ref("avg(response)"))
+        )
+    );
+  }
+
+  protected void assertPhysicalPlan(PhysicalPlan expected, LogicalPlan logicalPlan) {
+    assertEquals(expected, analyze(logicalPlan));
+  }
+
+  protected PhysicalPlan analyze(LogicalPlan logicalPlan) {
+    return new Planner(storageEngine).plan(logicalPlan);
+  }
+
+  protected class MockTable extends LogicalPlanNodeVisitor<PhysicalPlan, Object> implements Table {
+
+    @Override
+    public Map<String, ExprType> getFieldTypes() {
+      throw new UnsupportedOperationException();
+    }
 
-    @BeforeEach
-    public void setUp() {
-        when(storageEngine.getTable(any())).thenReturn(new MockTable());
+    @Override
+    public PhysicalPlan implement(LogicalPlan plan) {
+      return plan.accept(this, null);
     }
 
-    @Test
-    public void planner_test() {
-        assertPhysicalPlan(
-                PhysicalPlanDSL.rename(
-                        PhysicalPlanDSL.agg(
-                                PhysicalPlanDSL.filter(
-                                        scan,
-                                        dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(10))
-                                ),
-                                ImmutableList.of(dsl.avg(typeEnv(), DSL.ref("response"))),
-                                ImmutableList.of()
-                        ),
-                        ImmutableMap.of(DSL.ref("ivalue"), DSL.ref("avg(response)"))
-                ),
-                LogicalPlanDSL.rename(
-                        LogicalPlanDSL.aggregation(
-                                LogicalPlanDSL.filter(
-                                        LogicalPlanDSL.relation("schema"),
-                                        dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(10))
-                                ),
-                                ImmutableList.of(dsl.avg(typeEnv(), DSL.ref("response"))),
-                                ImmutableList.of()
-                        ),
-                        ImmutableMap.of(DSL.ref("ivalue"), DSL.ref("avg(response)"))
-                )
-        );
+    @Override
+    public PhysicalPlan visitRelation(LogicalRelation plan, Object context) {
+      return scan;
     }
 
-    protected void assertPhysicalPlan(PhysicalPlan expected, LogicalPlan logicalPlan) {
-        assertEquals(expected, analyze(logicalPlan));
+    @Override
+    public PhysicalPlan visitFilter(LogicalFilter plan, Object context) {
+      return new FilterOperator(plan.getChild().get(0).accept(this, context), plan.getCondition());
     }
 
-    protected PhysicalPlan analyze(LogicalPlan logicalPlan) {
-        return new Planner(storageEngine).plan(logicalPlan);
+    @Override
+    public PhysicalPlan visitAggregation(LogicalAggregation plan, Object context) {
+      return new AggregationOperator(plan.getChild().get(0).accept(this, context),
+          plan.getAggregatorList(), plan.getGroupByList()
+      );
     }
 
-    protected class MockTable extends LogicalPlanNodeVisitor<PhysicalPlan, Object> implements Table {
-
-        @Override
-        public Map<String, ExprType> getFieldTypes() {
-            throw new UnsupportedOperationException();
-        }
-
-        @Override
-        public PhysicalPlan implement(LogicalPlan plan) {
-            return plan.accept(this, null);
-        }
-
-        @Override
-        public PhysicalPlan visitRelation(LogicalRelation plan, Object context) {
-            return scan;
-        }
-
-        @Override
-        public PhysicalPlan visitFilter(LogicalFilter plan, Object context) {
-            return new FilterOperator(plan.getChild().get(0).accept(this, context), plan.getCondition());
-        }
-
-        @Override
-        public PhysicalPlan visitAggregation(LogicalAggregation plan, Object context) {
-            return new AggregationOperator(plan.getChild().get(0).accept(this, context),
-                    plan.getAggregatorList(), plan.getGroupByList()
-            );
-        }
-
-        @Override
-        public PhysicalPlan visitRename(LogicalRename plan, Object context) {
-            return new RenameOperator(plan.getChild().get(0).accept(this, context),
-                    plan.getRenameMap());
-        }
+    @Override
+    public PhysicalPlan visitRename(LogicalRename plan, Object context) {
+      return new RenameOperator(plan.getChild().get(0).accept(this, context),
+          plan.getRenameMap());
     }
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEvalTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEvalTest.java
index 17c86ab061..7081d487f3 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEvalTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalEvalTest.java
@@ -32,7 +32,8 @@
 
 @ExtendWith(MockitoExtension.class)
 public class LogicalEvalTest extends AnalyzerTestBase {
-  @Mock private Environment<Expression, ExprType> environment;
+  @Mock
+  private Environment<Expression, ExprType> environment;
 
   @Test
   public void analyze_eval_with_one_field() {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanNodeVisitorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanNodeVisitorTest.java
index 53157ac01b..4f9dcb2107 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanNodeVisitorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalPlanNodeVisitorTest.java
@@ -31,12 +31,17 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-/** Todo. Temporary added for UT coverage, Will be removed. */
+/**
+ * Todo. Temporary added for UT coverage, Will be removed.
+ */
 @ExtendWith(MockitoExtension.class)
 class LogicalPlanNodeVisitorTest {
-  @Mock Expression expression;
-  @Mock ReferenceExpression ref;
-  @Mock Aggregator aggregator;
+  @Mock
+  Expression expression;
+  @Mock
+  ReferenceExpression ref;
+  @Mock
+  Aggregator aggregator;
 
   @Test
   public void logicalPlanShouldTraversable() {
@@ -55,26 +60,42 @@ public void logicalPlanShouldTraversable() {
   @Test
   public void testAbstractPlanNodeVisitorShouldReturnNull() {
     LogicalPlan relation = LogicalPlanDSL.relation("schema");
+    assertNull(relation.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan filter = LogicalPlanDSL.filter(relation, expression);
+    assertNull(filter.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan aggregation =
         LogicalPlanDSL.aggregation(
             filter, ImmutableList.of(aggregator), ImmutableList.of(expression));
+    assertNull(aggregation.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan rename = LogicalPlanDSL.rename(aggregation, ImmutableMap.of(ref, ref));
+    assertNull(rename.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan project = LogicalPlanDSL.project(relation, ref);
+    assertNull(project.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan remove = LogicalPlanDSL.remove(relation, ref);
+    assertNull(remove.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan eval = LogicalPlanDSL.eval(relation, Pair.of(ref, expression));
+    assertNull(eval.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     LogicalPlan sort = LogicalPlanDSL.sort(relation, 100, Pair.of(SortOption.PPL_ASC, expression));
-    LogicalPlan dedup = LogicalPlanDSL.dedupe(relation, 1, false, false, expression);
+    assertNull(sort.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
 
-    assertNull(relation.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(filter.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(aggregation.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(rename.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(project.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(remove.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(eval.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(sort.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(dedup.accept(new LogicalPlanNodeVisitor<Integer, Object>() {}, null));
+    LogicalPlan dedup = LogicalPlanDSL.dedupe(relation, 1, false, false, expression);
+    assertNull(dedup.accept(new LogicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
   }
 
   private static class NodesCount extends LogicalPlanNodeVisitor<Integer, Object> {
@@ -87,24 +108,24 @@ public Integer visitRelation(LogicalRelation plan, Object context) {
     public Integer visitFilter(LogicalFilter plan, Object context) {
       return 1
           + plan.getChild().stream()
-              .map(child -> child.accept(this, context))
-              .collect(Collectors.summingInt(Integer::intValue));
+          .map(child -> child.accept(this, context))
+          .collect(Collectors.summingInt(Integer::intValue));
     }
 
     @Override
     public Integer visitAggregation(LogicalAggregation plan, Object context) {
       return 1
           + plan.getChild().stream()
-              .map(child -> child.accept(this, context))
-              .collect(Collectors.summingInt(Integer::intValue));
+          .map(child -> child.accept(this, context))
+          .collect(Collectors.summingInt(Integer::intValue));
     }
 
     @Override
     public Integer visitRename(LogicalRename plan, Object context) {
       return 1
           + plan.getChild().stream()
-              .map(child -> child.accept(this, context))
-              .collect(Collectors.summingInt(Integer::intValue));
+          .map(child -> child.accept(this, context))
+          .collect(Collectors.summingInt(Integer::intValue));
     }
   }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelationTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelationTest.java
index b860b45007..543c7a01ac 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelationTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/logical/LogicalRelationTest.java
@@ -15,15 +15,15 @@
 
 package com.amazon.opendistroforelasticsearch.sql.planner.logical;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.Test;
+
 class LogicalRelationTest {
 
-    @Test
-    public void logicalRelationHasNoInput() {
-        LogicalPlan relation = LogicalPlanDSL.relation("index");
-        assertEquals(0, relation.getChild().size());
-    }
+  @Test
+  public void logicalRelationHasNoInput() {
+    LogicalPlan relation = LogicalPlanDSL.relation("index");
+    assertEquals(0, relation.getChild().size());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperatorTest.java
index d703c50577..ad464e190e 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/AggregationOperatorTest.java
@@ -29,43 +29,46 @@
 import org.junit.jupiter.api.Test;
 
 class AggregationOperatorTest extends PhysicalPlanTestBase {
-    @Test
-    public void avg_with_one_groups() {
-        PhysicalPlan plan = new AggregationOperator(new TestScan(),
-                Collections.singletonList(dsl.avg(typeEnv(), DSL.ref("response"))),
-                Collections.singletonList(DSL.ref("action")));
-        List<ExprValue> result = execute(plan);
-        assertEquals(2, result.size());
-        assertThat(result, containsInAnyOrder(
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "avg(response)", 268d)),
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "avg(response)", 350d))
-        ));
-    }
+  @Test
+  public void avg_with_one_groups() {
+    PhysicalPlan plan = new AggregationOperator(new TestScan(),
+        Collections.singletonList(dsl.avg(typeEnv(), DSL.ref("response"))),
+        Collections.singletonList(DSL.ref("action")));
+    List<ExprValue> result = execute(plan);
+    assertEquals(2, result.size());
+    assertThat(result, containsInAnyOrder(
+        ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "avg(response)", 268d)),
+        ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "avg(response)", 350d))
+    ));
+  }
 
-    @Test
-    public void avg_with_two_groups() {
-        PhysicalPlan plan = new AggregationOperator(new TestScan(),
-                Collections.singletonList(dsl.avg(typeEnv(), DSL.ref("response"))),
-                Arrays.asList(DSL.ref("action"), DSL.ref("ip")));
-        List<ExprValue> result = execute(plan);
-        assertEquals(3, result.size());
-        assertThat(result, containsInAnyOrder(
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "ip", "209.160.24.63", "avg(response)", 302d)),
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "ip", "112.111.162.4", "avg(response)", 200d)),
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "ip", "74.125.19.106", "avg(response)", 350d))
-        ));
-    }
+  @Test
+  public void avg_with_two_groups() {
+    PhysicalPlan plan = new AggregationOperator(new TestScan(),
+        Collections.singletonList(dsl.avg(typeEnv(), DSL.ref("response"))),
+        Arrays.asList(DSL.ref("action"), DSL.ref("ip")));
+    List<ExprValue> result = execute(plan);
+    assertEquals(3, result.size());
+    assertThat(result, containsInAnyOrder(
+        ExprValueUtils.tupleValue(
+            ImmutableMap.of("action", "GET", "ip", "209.160.24.63", "avg(response)", 302d)),
+        ExprValueUtils.tupleValue(
+            ImmutableMap.of("action", "GET", "ip", "112.111.162.4", "avg(response)", 200d)),
+        ExprValueUtils.tupleValue(
+            ImmutableMap.of("action", "POST", "ip", "74.125.19.106", "avg(response)", 350d))
+    ));
+  }
 
-    @Test
-    public void sum_with_one_groups() {
-        PhysicalPlan plan = new AggregationOperator(new TestScan(),
-                Collections.singletonList(dsl.sum(typeEnv(), DSL.ref("response"))),
-                Collections.singletonList(DSL.ref("action")));
-        List<ExprValue> result = execute(plan);
-        assertEquals(2, result.size());
-        assertThat(result, containsInAnyOrder(
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "sum(response)", 804)),
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "sum(response)", 700))
-        ));
-    }
+  @Test
+  public void sum_with_one_groups() {
+    PhysicalPlan plan = new AggregationOperator(new TestScan(),
+        Collections.singletonList(dsl.sum(typeEnv(), DSL.ref("response"))),
+        Collections.singletonList(DSL.ref("action")));
+    List<ExprValue> result = execute(plan);
+    assertEquals(2, result.size());
+    assertThat(result, containsInAnyOrder(
+        ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "sum(response)", 804)),
+        ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "sum(response)", 700))
+    ));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperatorTest.java
index 7906f89eb2..5bb57a506d 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/DedupeOperatorTest.java
@@ -34,13 +34,14 @@
 
 @ExtendWith(MockitoExtension.class)
 class DedupeOperatorTest extends PhysicalPlanTestBase {
-  @Mock private PhysicalPlan inputPlan;
+  @Mock
+  private PhysicalPlan inputPlan;
 
   /**
    * construct the map which contain null value, because {@link ImmutableMap} doesn't support null
    * value.
    */
-  private Map<String, Object> NULL_MAP =
+  private static final Map<String, Object> NULL_MAP =
       new HashMap<String, Object>() {
         {
           put("region", null);
@@ -190,7 +191,7 @@ public void dedupe_one_field_with_missing_value() {
         .thenReturn(
             tupleValue(ImmutableMap.of("region", "us-east-1", "action", "POST", "response", 200)))
         .thenReturn(
-            tupleValue(ImmutableMap.of( "action", "POST", "response", 200)))
+            tupleValue(ImmutableMap.of("action", "POST", "response", 200)))
         .thenReturn(
             tupleValue(ImmutableMap.of("region", "us-east-1", "action", "GET", "response", 200)));
 
@@ -209,7 +210,7 @@ public void dedupe_one_field_with_missing_value_keep_empty() {
         .thenReturn(
             tupleValue(ImmutableMap.of("region", "us-east-1", "action", "POST", "response", 200)))
         .thenReturn(
-            tupleValue(ImmutableMap.of( "action", "POST", "response", 200)))
+            tupleValue(ImmutableMap.of("action", "POST", "response", 200)))
         .thenReturn(
             tupleValue(ImmutableMap.of("region", "us-east-1", "action", "GET", "response", 200)));
 
@@ -217,7 +218,7 @@ public void dedupe_one_field_with_missing_value_keep_empty() {
         execute(dedupe(inputPlan, 1, true, false, DSL.ref("region"))),
         contains(
             tupleValue(ImmutableMap.of("region", "us-east-1", "action", "GET", "response", 200)),
-            tupleValue(ImmutableMap.of( "action", "POST", "response", 200))));
+            tupleValue(ImmutableMap.of("action", "POST", "response", 200))));
   }
 
   @Test
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperatorTest.java
index b81f3039ab..63b676d602 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/EvalOperatorTest.java
@@ -38,8 +38,10 @@
 
 @ExtendWith(MockitoExtension.class)
 class EvalOperatorTest extends PhysicalPlanTestBase {
-  @Mock private PhysicalPlan inputPlan;
-  @Mock private Environment<Expression, ExprType> environment;
+  @Mock
+  private PhysicalPlan inputPlan;
+  @Mock
+  private Environment<Expression, ExprType> environment;
 
   @Test
   public void create_new_field_that_contain_the_result_of_a_calculation() {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperatorTest.java
index f3828b3126..8d4d379f43 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/FilterOperatorTest.java
@@ -28,13 +28,15 @@
 
 class FilterOperatorTest extends PhysicalPlanTestBase {
 
-    @Test
-    public void filterTest() {
-        FilterOperator plan = new FilterOperator(new TestScan(),
-                dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(404)));
-        List<ExprValue> result = execute(plan);
-        assertEquals(1, result.size());
-        assertThat(result, containsInAnyOrder(ExprValueUtils
-                .tupleValue(ImmutableMap.of("ip", "209.160.24.63", "action", "GET", "response", 404, "referer", "www.amazon.com"))));
-    }
+  @Test
+  public void filterTest() {
+    FilterOperator plan = new FilterOperator(new TestScan(),
+        dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(404)));
+    List<ExprValue> result = execute(plan);
+    assertEquals(1, result.size());
+    assertThat(result, containsInAnyOrder(ExprValueUtils
+        .tupleValue(ImmutableMap
+            .of("ip", "209.160.24.63", "action", "GET", "response", 404, "referer",
+                "www.amazon.com"))));
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitorTest.java
index 01dcd6b788..59f0ff4906 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanNodeVisitorTest.java
@@ -15,6 +15,9 @@
 
 package com.amazon.opendistroforelasticsearch.sql.planner.physical;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
 import com.amazon.opendistroforelasticsearch.sql.ast.tree.Sort.SortOption;
 import com.amazon.opendistroforelasticsearch.sql.expression.DSL;
 import com.amazon.opendistroforelasticsearch.sql.expression.ReferenceExpression;
@@ -27,14 +30,15 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNull;
-
-/** Todo, testing purpose, delete later. */
+/**
+ * Todo, testing purpose, delete later.
+ */
 @ExtendWith(MockitoExtension.class)
 class PhysicalPlanNodeVisitorTest extends PhysicalPlanTestBase {
-  @Mock PhysicalPlan plan;
-  @Mock ReferenceExpression ref;
+  @Mock
+  PhysicalPlan plan;
+  @Mock
+  ReferenceExpression ref;
 
   @Test
   public void print_physical_plan() {
@@ -67,26 +71,40 @@ public void test_PhysicalPlanVisitor_should_return_null() {
     PhysicalPlan filter =
         PhysicalPlanDSL.filter(
             new TestScan(), dsl.equal(typeEnv(), DSL.ref("response"), DSL.literal(10)));
+    assertNull(filter.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     PhysicalPlan aggregation =
         PhysicalPlanDSL.agg(
             filter, ImmutableList.of(dsl.avg(typeEnv(), DSL.ref("response"))), ImmutableList.of());
+    assertNull(aggregation.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     PhysicalPlan rename =
         PhysicalPlanDSL.rename(
             aggregation, ImmutableMap.of(DSL.ref("ivalue"), DSL.ref("avg(response)")));
+    assertNull(rename.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     PhysicalPlan project = PhysicalPlanDSL.project(plan, ref);
+    assertNull(project.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     PhysicalPlan remove = PhysicalPlanDSL.remove(plan, ref);
+    assertNull(remove.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     PhysicalPlan eval = PhysicalPlanDSL.eval(plan, Pair.of(ref, ref));
+    assertNull(eval.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
+
     PhysicalPlan sort = PhysicalPlanDSL.sort(plan, 100, Pair.of(SortOption.PPL_ASC, ref));
-    PhysicalPlan dedupe = PhysicalPlanDSL.dedupe(plan, ref);
+    assertNull(sort.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
 
-    assertNull(filter.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(aggregation.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(rename.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(project.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(remove.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(eval.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(sort.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
-    assertNull(dedupe.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {}, null));
+    PhysicalPlan dedupe = PhysicalPlanDSL.dedupe(plan, ref);
+    assertNull(dedupe.accept(new PhysicalPlanNodeVisitor<Integer, Object>() {
+    }, null));
   }
 
   public static class PhysicalPlanPrinter extends PhysicalPlanNodeVisitor<String, Integer> {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanTestBase.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanTestBase.java
index a4a89f8897..33be16490f 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanTestBase.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/PhysicalPlanTestBase.java
@@ -40,72 +40,81 @@
 @ExtendWith(SpringExtension.class)
 @ContextConfiguration(classes = {ExpressionConfig.class})
 public class PhysicalPlanTestBase {
-    @Autowired
-    protected DSL dsl;
+  @Autowired
+  protected DSL dsl;
 
-    private static final List<ExprValue> inputs = new ImmutableList.Builder<ExprValue>()
-            .add(ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63", "action", "GET", "response", 200, "referer", "www.amazon.com")))
-            .add(ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63", "action", "GET", "response", 404, "referer", "www.amazon.com")))
-            .add(ExprValueUtils.tupleValue(ImmutableMap.of("ip", "112.111.162.4", "action", "GET", "response", 200, "referer", "www.amazon.com")))
-            .add(ExprValueUtils.tupleValue(ImmutableMap.of("ip", "74.125.19.106", "action", "POST", "response", 200, "referer", "www.google.com")))
-            .add(ExprValueUtils.tupleValue(ImmutableMap.of("ip", "74.125.19.106", "action", "POST", "response", 500)))
-            .build();
+  private static final List<ExprValue> inputs = new ImmutableList.Builder<ExprValue>()
+      .add(ExprValueUtils.tupleValue(ImmutableMap
+          .of("ip", "209.160.24.63", "action", "GET", "response", 200, "referer",
+              "www.amazon.com")))
+      .add(ExprValueUtils.tupleValue(ImmutableMap
+          .of("ip", "209.160.24.63", "action", "GET", "response", 404, "referer",
+              "www.amazon.com")))
+      .add(ExprValueUtils.tupleValue(ImmutableMap
+          .of("ip", "112.111.162.4", "action", "GET", "response", 200, "referer",
+              "www.amazon.com")))
+      .add(ExprValueUtils.tupleValue(ImmutableMap
+          .of("ip", "74.125.19.106", "action", "POST", "response", 200, "referer",
+              "www.google.com")))
+      .add(ExprValueUtils
+          .tupleValue(ImmutableMap.of("ip", "74.125.19.106", "action", "POST", "response", 500)))
+      .build();
 
-    private static Map<String, ExprType> typeMapping = new ImmutableMap.Builder<String, ExprType>()
-            .put("ip", ExprType.STRING)
-            .put("action", ExprType.STRING)
-            .put("response", ExprType.INTEGER)
-            .put("referer", ExprType.STRING)
-            .build();
+  private static Map<String, ExprType> typeMapping = new ImmutableMap.Builder<String, ExprType>()
+      .put("ip", ExprType.STRING)
+      .put("action", ExprType.STRING)
+      .put("response", ExprType.INTEGER)
+      .put("referer", ExprType.STRING)
+      .build();
 
-    @Bean
-    protected Environment<Expression, ExprType> typeEnv() {
-        return var -> {
-            if (var instanceof ReferenceExpression) {
-                ReferenceExpression refExpr = (ReferenceExpression) var;
-                if (typeMapping.containsKey(refExpr.getAttr())) {
-                    return typeMapping.get(refExpr.getAttr());
-                }
-            }
-            throw new ExpressionEvaluationException("type resolved failed");
-        };
-    }
-
-    protected List<ExprValue> execute(PhysicalPlan plan) {
-        ImmutableList.Builder<ExprValue> builder = new ImmutableList.Builder<>();
-        plan.open();
-        while (plan.hasNext()) {
-            builder.add(plan.next());
+  @Bean
+  protected Environment<Expression, ExprType> typeEnv() {
+    return var -> {
+      if (var instanceof ReferenceExpression) {
+        ReferenceExpression refExpr = (ReferenceExpression) var;
+        if (typeMapping.containsKey(refExpr.getAttr())) {
+          return typeMapping.get(refExpr.getAttr());
         }
-        plan.close();
-        return builder.build();
+      }
+      throw new ExpressionEvaluationException("type resolved failed");
+    };
+  }
+
+  protected List<ExprValue> execute(PhysicalPlan plan) {
+    ImmutableList.Builder<ExprValue> builder = new ImmutableList.Builder<>();
+    plan.open();
+    while (plan.hasNext()) {
+      builder.add(plan.next());
     }
+    plan.close();
+    return builder.build();
+  }
 
-    protected static class TestScan extends PhysicalPlan {
-        private final Iterator<ExprValue> iterator;
+  protected static class TestScan extends PhysicalPlan {
+    private final Iterator<ExprValue> iterator;
 
-        public TestScan() {
-            iterator = inputs.iterator();
-        }
+    public TestScan() {
+      iterator = inputs.iterator();
+    }
 
-        @Override
-        public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
-            return null;
-        }
+    @Override
+    public <R, C> R accept(PhysicalPlanNodeVisitor<R, C> visitor, C context) {
+      return null;
+    }
 
-        @Override
-        public List<PhysicalPlan> getChild() {
-            return ImmutableList.of();
-        }
+    @Override
+    public List<PhysicalPlan> getChild() {
+      return ImmutableList.of();
+    }
 
-        @Override
-        public boolean hasNext() {
-            return iterator.hasNext();
-        }
+    @Override
+    public boolean hasNext() {
+      return iterator.hasNext();
+    }
 
-        @Override
-        public ExprValue next() {
-            return iterator.next();
-        }
+    @Override
+    public ExprValue next() {
+      return iterator.next();
     }
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperatorTest.java
index ba961fd89d..a3526459e2 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/ProjectOperatorTest.java
@@ -35,7 +35,8 @@
 @ExtendWith(MockitoExtension.class)
 class ProjectOperatorTest extends PhysicalPlanTestBase {
 
-  @Mock private PhysicalPlan inputPlan;
+  @Mock
+  private PhysicalPlan inputPlan;
 
   @Test
   public void project_one_field() {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperatorTest.java
index 9a706c4091..1eea059fff 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RemoveOperatorTest.java
@@ -34,7 +34,8 @@
 
 @ExtendWith(MockitoExtension.class)
 class RemoveOperatorTest extends PhysicalPlanTestBase {
-  @Mock private PhysicalPlan inputPlan;
+  @Mock
+  private PhysicalPlan inputPlan;
 
   @Test
   public void remove_one_field() {
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperatorTest.java
index ff50d3c9a4..637af9ed3e 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/RenameOperatorTest.java
@@ -33,35 +33,35 @@
 
 @ExtendWith(MockitoExtension.class)
 public class RenameOperatorTest extends PhysicalPlanTestBase {
-    @Mock
-    private PhysicalPlan inputPlan;
+  @Mock
+  private PhysicalPlan inputPlan;
 
-    @Test
-    public void avg_aggregation_rename() {
-        PhysicalPlan plan = new RenameOperator(
-                new AggregationOperator(new TestScan(),
-                        Collections.singletonList(dsl.avg(typeEnv(), DSL.ref("response"))),
-                        Collections.singletonList(DSL.ref("action"))),
-                ImmutableMap.of(DSL.ref("avg(response)"), DSL.ref("avg"))
-        );
-        List<ExprValue> result = execute(plan);
-        assertEquals(2, result.size());
-        assertThat(result, containsInAnyOrder(
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "avg", 268d)),
-                ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "avg", 350d))
-        ));
-    }
+  @Test
+  public void avg_aggregation_rename() {
+    PhysicalPlan plan = new RenameOperator(
+        new AggregationOperator(new TestScan(),
+            Collections.singletonList(dsl.avg(typeEnv(), DSL.ref("response"))),
+            Collections.singletonList(DSL.ref("action"))),
+        ImmutableMap.of(DSL.ref("avg(response)"), DSL.ref("avg"))
+    );
+    List<ExprValue> result = execute(plan);
+    assertEquals(2, result.size());
+    assertThat(result, containsInAnyOrder(
+        ExprValueUtils.tupleValue(ImmutableMap.of("action", "GET", "avg", 268d)),
+        ExprValueUtils.tupleValue(ImmutableMap.of("action", "POST", "avg", 350d))
+    ));
+  }
 
-    @Test
-    public void rename_int_value() {
-        when(inputPlan.hasNext()).thenReturn(true, false);
-        when(inputPlan.next()).thenReturn(ExprValueUtils.integerValue(1));
-        PhysicalPlan plan = new RenameOperator(
-                inputPlan,
-                ImmutableMap.of(DSL.ref("avg(response)"), DSL.ref("avg"))
-        );
-        List<ExprValue> result = execute(plan);
-        assertEquals(1, result.size());
-        assertThat(result, containsInAnyOrder(ExprValueUtils.integerValue(1)));
-    }
+  @Test
+  public void rename_int_value() {
+    when(inputPlan.hasNext()).thenReturn(true, false);
+    when(inputPlan.next()).thenReturn(ExprValueUtils.integerValue(1));
+    PhysicalPlan plan = new RenameOperator(
+        inputPlan,
+        ImmutableMap.of(DSL.ref("avg(response)"), DSL.ref("avg"))
+    );
+    List<ExprValue> result = execute(plan);
+    assertEquals(1, result.size());
+    assertThat(result, containsInAnyOrder(ExprValueUtils.integerValue(1)));
+  }
 }
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperatorTest.java
index d046fe94a1..12550c123c 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/planner/physical/SortOperatorTest.java
@@ -35,13 +35,14 @@
 
 @ExtendWith(MockitoExtension.class)
 class SortOperatorTest extends PhysicalPlanTestBase {
-  @Mock private PhysicalPlan inputPlan;
+  @Mock
+  private PhysicalPlan inputPlan;
 
   /**
    * construct the map which contain null value, because {@link ImmutableMap} doesn't support null
    * value.
    */
-  private Map<String, Object> NULL_MAP =
+  private static final Map<String, Object> NULL_MAP =
       new HashMap<String, Object>() {
         {
           put("size", 399);
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperatorTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperatorTest.java
index 918a2ff2cc..25869deee9 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperatorTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/TableScanOperatorTest.java
@@ -16,47 +16,47 @@
 
 package com.amazon.opendistroforelasticsearch.sql.storage;
 
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlanNodeVisitor;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 class TableScanOperatorTest {
 
-    private final TableScanOperator tableScan = new TableScanOperator() {
-        @Override
-        public boolean hasNext() {
-            return false;
-        }
-
-        @Override
-        public ExprValue next() {
-            return null;
-        }
-    };
-
-    @Test
-    public void accept() {
-        Boolean isVisited = tableScan.accept(new PhysicalPlanNodeVisitor<Boolean, Object>() {
-            @Override
-            protected Boolean visitNode(PhysicalPlan node, Object context) {
-                return (node instanceof TableScanOperator);
-            }
-
-            @Override
-            public Boolean visitTableScan(TableScanOperator node, Object context) {
-                return super.visitTableScan(node, context);
-            }
-        }, null);
-
-        assertTrue(isVisited);
+  private final TableScanOperator tableScan = new TableScanOperator() {
+    @Override
+    public boolean hasNext() {
+      return false;
     }
 
-    @Test
-    public void getChild() {
-        assertTrue(tableScan.getChild().isEmpty());
+    @Override
+    public ExprValue next() {
+      return null;
     }
+  };
+
+  @Test
+  public void accept() {
+    Boolean isVisited = tableScan.accept(new PhysicalPlanNodeVisitor<Boolean, Object>() {
+      @Override
+      protected Boolean visitNode(PhysicalPlan node, Object context) {
+        return (node instanceof TableScanOperator);
+      }
+
+      @Override
+      public Boolean visitTableScan(TableScanOperator node, Object context) {
+        return super.visitTableScan(node, context);
+      }
+    }, null);
+
+    assertTrue(isVisited);
+  }
+
+  @Test
+  public void getChild() {
+    assertTrue(tableScan.getChild().isEmpty());
+  }
 
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTupleTest.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTupleTest.java
index 1f8bb9c741..2820608da4 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTupleTest.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/storage/bindingtuple/BindingTupleTest.java
@@ -25,28 +25,31 @@
 import org.junit.jupiter.api.Test;
 
 class BindingTupleTest {
-    @Test
-    public void resolve_ref_expression() {
-        BindingTuple bindingTuple = ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63")).bindingTuples();
-        assertEquals(ExprValueUtils.stringValue("209.160.24.63"), bindingTuple.resolve(DSL.ref("ip")));
-    }
+  @Test
+  public void resolve_ref_expression() {
+    BindingTuple bindingTuple =
+        ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63")).bindingTuples();
+    assertEquals(ExprValueUtils.stringValue("209.160.24.63"), bindingTuple.resolve(DSL.ref("ip")));
+  }
 
-    @Test
-    public void resolve_missing_expression() {
-        BindingTuple bindingTuple = ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63")).bindingTuples();
-        assertEquals(ExprValueUtils.LITERAL_MISSING, bindingTuple.resolve(DSL.ref("ip_missing")));
-    }
+  @Test
+  public void resolve_missing_expression() {
+    BindingTuple bindingTuple =
+        ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63")).bindingTuples();
+    assertEquals(ExprValueUtils.LITERAL_MISSING, bindingTuple.resolve(DSL.ref("ip_missing")));
+  }
 
-    @Test
-    public void resolve_from_empty_tuple() {
-        assertEquals(ExprValueUtils.LITERAL_MISSING, BindingTuple.EMPTY.resolve(DSL.ref("ip_missing")));
-    }
+  @Test
+  public void resolve_from_empty_tuple() {
+    assertEquals(ExprValueUtils.LITERAL_MISSING, BindingTuple.EMPTY.resolve(DSL.ref("ip_missing")));
+  }
 
-    @Test
-    public void resolve_literal_expression_throw_exception() {
-        BindingTuple bindingTuple = ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63")).bindingTuples();
-        ExpressionEvaluationException exception = assertThrows
-                (ExpressionEvaluationException.class, () -> bindingTuple.resolve(DSL.literal(1)));
-        assertEquals("can resolve expression: 1", exception.getMessage());
-    }
+  @Test
+  public void resolve_literal_expression_throw_exception() {
+    BindingTuple bindingTuple =
+        ExprValueUtils.tupleValue(ImmutableMap.of("ip", "209.160.24.63")).bindingTuples();
+    ExpressionEvaluationException exception = assertThrows(ExpressionEvaluationException.class,
+        () -> bindingTuple.resolve(DSL.literal(1)));
+    assertEquals("can resolve expression: 1", exception.getMessage());
+  }
 }
\ No newline at end of file
diff --git a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/utils/MatcherUtils.java b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/utils/MatcherUtils.java
index 6fa68c2547..7b2a8d8766 100644
--- a/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/utils/MatcherUtils.java
+++ b/core/src/test/java/com/amazon/opendistroforelasticsearch/sql/utils/MatcherUtils.java
@@ -15,67 +15,46 @@
 
 package com.amazon.opendistroforelasticsearch.sql.utils;
 
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprTupleValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
-import com.amazon.opendistroforelasticsearch.sql.expression.DSL;
 import org.hamcrest.Description;
 import org.hamcrest.TypeSafeMatcher;
 
-import java.util.Map;
-
+/**
+ * Matcher Utils.
+ */
 public class MatcherUtils {
-    public static TypeSafeMatcher<ExprValue> tuple(Map<String, Object> map) {
-        return new TypeSafeMatcher<ExprValue>() {
-            @Override
-            public void describeTo(Description description) {
-                description.appendText(map.toString());
-            }
-
-            @Override
-            protected boolean matchesSafely(ExprValue value) {
-                if (ExprType.STRUCT == value.type()) {
-                    ExprTupleValue tupleValue = (ExprTupleValue) value;
-                    for (Map.Entry<String, Object> entry : map.entrySet()) {
-                        if (!tupleValue.bindingTuples().resolve(DSL.ref(entry.getKey()))
-                                .equals(ExprValueUtils.fromObjectValue(entry.getValue()))) {
-                            return false;
-                        }
-                    }
-                    return true;
-                } else {
-                    return false;
-                }
-            }
-        };
-    }
-
-    public static TypeSafeMatcher<ExprValue> hasType(ExprType type) {
-        return new TypeSafeMatcher<ExprValue>() {
-            @Override
-            public void describeTo(Description description) {
-                description.appendText(type.toString());
-            }
-
-            @Override
-            protected boolean matchesSafely(ExprValue value) {
-                return type == value.type();
-            }
-        };
-    }
-
-    public static TypeSafeMatcher<ExprValue> hasValue(Object object) {
-        return new TypeSafeMatcher<ExprValue>() {
-            @Override
-            public void describeTo(Description description) {
-                description.appendText(object.toString());
-            }
-
-            @Override
-            protected boolean matchesSafely(ExprValue value) {
-                return object.equals(value.value());
-            }
-        };
-    }
+  /**
+   * Check {@link ExprValue} type equal to {@link ExprType}.
+   */
+  public static TypeSafeMatcher<ExprValue> hasType(ExprType type) {
+    return new TypeSafeMatcher<ExprValue>() {
+      @Override
+      public void describeTo(Description description) {
+        description.appendText(type.toString());
+      }
+
+      @Override
+      protected boolean matchesSafely(ExprValue value) {
+        return type == value.type();
+      }
+    };
+  }
+
+  /**
+   * Check {@link ExprValue} value equal to {@link Object}.
+   */
+  public static TypeSafeMatcher<ExprValue> hasValue(Object object) {
+    return new TypeSafeMatcher<ExprValue>() {
+      @Override
+      public void describeTo(Description description) {
+        description.appendText(object.toString());
+      }
+
+      @Override
+      protected boolean matchesSafely(ExprValue value) {
+        return object.equals(value.value());
+      }
+    };
+  }
 }
diff --git a/elasticsearch/build.gradle b/elasticsearch/build.gradle
index 6a2688f598..f46fb69390 100644
--- a/elasticsearch/build.gradle
+++ b/elasticsearch/build.gradle
@@ -11,7 +11,7 @@ repositories {
 dependencies {
     compile project(':core')
     compile group: 'org.elasticsearch', name: 'elasticsearch', version: "${es_version}"
-    compile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-high-level-client', version:"${es_version}"
+    compile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-high-level-client', version: "${es_version}"
 
     testImplementation('org.junit.jupiter:junit-jupiter:5.6.2')
     testCompile group: 'org.hamcrest', name: 'hamcrest-library', version: '2.1'
@@ -46,7 +46,7 @@ jacocoTestCoverageVerification {
         rule {
             element = 'CLASS'
             excludes = [
-                'com.amazon.opendistroforelasticsearch.sql.elasticsearch.security.SecurityAccess'
+                    'com.amazon.opendistroforelasticsearch.sql.elasticsearch.security.SecurityAccess'
             ]
             limit {
                 minimum = 1.0
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchClient.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchClient.java
index 2b1c06fc18..13a82ac751 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchClient.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchClient.java
@@ -19,39 +19,41 @@
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.mapping.IndexMapping;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.request.ElasticsearchRequest;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
-
 import java.util.Map;
 
 /**
- * Elasticsearch client abstraction to wrap different Elasticsearch client implementation.
- * For example, implementation by node client for ES plugin or by REST client for standalone mode.
+ * Elasticsearch client abstraction to wrap different Elasticsearch client implementation. For
+ * example, implementation by node client for ES plugin or by REST client for standalone mode.
  */
 public interface ElasticsearchClient {
 
-    /**
-     * Fetch index mapping(s) according to index expression given
-     * @param indexExpression  index expression
-     * @return                 index mapping(s) from index name to its mapping
-     */
-    Map<String, IndexMapping> getIndexMappings(String indexExpression);
-
-    /**
-     * Perform search query in the search request.
-     * @param request       search request
-     * @return              search response
-     */
-    ElasticsearchResponse search(ElasticsearchRequest request);
-
-    /**
-     * Clean up resources related to the search request, for example scroll context.
-     * @param request       search request
-     */
-    void cleanup(ElasticsearchRequest request);
-
-    /**
-     * Schedule a task to run.
-     * @param task      task
-     */
-    void schedule(Runnable task);
-
+  /**
+   * Fetch index mapping(s) according to index expression given.
+   *
+   * @param indexExpression index expression
+   * @return index mapping(s) from index name to its mapping
+   */
+  Map<String, IndexMapping> getIndexMappings(String indexExpression);
+
+  /**
+   * Perform search query in the search request.
+   *
+   * @param request search request
+   * @return search response
+   */
+  ElasticsearchResponse search(ElasticsearchRequest request);
+
+  /**
+   * Clean up resources related to the search request, for example scroll context.
+   *
+   * @param request search request
+   */
+  void cleanup(ElasticsearchRequest request);
+
+  /**
+   * Schedule a task to run.
+   *
+   * @param task task
+   */
+  void schedule(Runnable task);
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClient.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClient.java
index 5abfb9f836..2e58fa8809 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClient.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClient.java
@@ -21,6 +21,11 @@
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
 import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
 import com.google.common.collect.ImmutableMap;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.function.Predicate;
 import lombok.RequiredArgsConstructor;
 import org.apache.logging.log4j.ThreadContext;
 import org.elasticsearch.action.search.SearchResponse;
@@ -34,127 +39,111 @@
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.threadpool.ThreadPool;
 
-import java.io.IOException;
-import java.util.Collections;
-import java.util.Map;
-import java.util.function.Function;
-import java.util.function.Predicate;
-
-/**
- * Elasticsearch connection by node client.
- */
+/** Elasticsearch connection by node client. */
 @RequiredArgsConstructor
 public class ElasticsearchNodeClient implements ElasticsearchClient {
 
-    /**
-     * Default types and field filter to match all
-     */
-    public static final String[] ALL_TYPES = new String[0];
-    public static final Function<String, Predicate<String>> ALL_FIELDS = (anyIndex -> (anyField -> true));
-
-    /**
-     * Current cluster state on local node
-     */
-    private final ClusterService clusterService;
-
-    /**
-     * Node client provided by Elasticsearch container.
-     */
-    private final NodeClient client;
-
-    /**
-     * Index name expression resolver to get concrete index name
-     */
-    private final IndexNameExpressionResolver resolver = new IndexNameExpressionResolver();
-
-
-    /**
-     * Get field mappings of index by an index expression. Majority is copied from legacy LocalClusterState.
-     *
-     * For simplicity, removed type (deprecated) and field filter in argument list.
-     * Also removed mapping cache, cluster state listener (mainly for performance and debugging).
-     *
-     * @param indexExpression     index name expression
-     * @return                    index mapping(s) in our class to isolate Elasticsearch API.
-     *                             IndexNotFoundException is thrown if no index matched.
-     */
-    @Override
-    public Map<String, IndexMapping> getIndexMappings(String indexExpression) {
-        try {
-            ClusterState state = clusterService.state();
-            String[] concreteIndices = resolveIndexExpression(state, new String[]{ indexExpression });
-
-            return populateIndexMappings(state.metaData().findMappings(concreteIndices, ALL_TYPES, ALL_FIELDS));
-        } catch (IOException e) {
-            throw new IllegalStateException(
-                "Failed to read mapping in cluster state for index pattern [" + indexExpression + "]", e);
-        }
-    }
-
-    /**
-     * TODO: Scroll doesn't work for aggregation. Support aggregation later.
-     */
-    @Override
-    public ElasticsearchResponse search(ElasticsearchRequest request) {
-        SearchResponse esResponse;
-        if (request.isScrollStarted()) {
-            esResponse = client.searchScroll(request.scrollRequest()).actionGet();
-        } else {
-            esResponse = client.search(request.searchRequest()).actionGet();
-        }
-        request.setScrollId(esResponse.getScrollId());
-
-        return new ElasticsearchResponse(esResponse);
-    }
-
-    @Override
-    public void cleanup(ElasticsearchRequest request) {
-        if (request.isScrollStarted()) {
-            client.prepareClearScroll().
-                   addScrollId(request.getScrollId()).
-                   get();
-            request.reset();
-        }
+  /** Default types and field filter to match all. */
+  public static final String[] ALL_TYPES = new String[0];
+
+  public static final Function<String, Predicate<String>> ALL_FIELDS =
+      (anyIndex -> (anyField -> true));
+
+  /** Current cluster state on local node. */
+  private final ClusterService clusterService;
+
+  /** Node client provided by Elasticsearch container. */
+  private final NodeClient client;
+
+  /** Index name expression resolver to get concrete index name. */
+  private final IndexNameExpressionResolver resolver = new IndexNameExpressionResolver();
+
+  /**
+   * Get field mappings of index by an index expression. Majority is copied from legacy
+   * LocalClusterState.
+   *
+   * <p>For simplicity, removed type (deprecated) and field filter in argument list. Also removed
+   * mapping cache, cluster state listener (mainly for performance and debugging).
+   *
+   * @param indexExpression index name expression
+   * @return index mapping(s) in our class to isolate Elasticsearch API. IndexNotFoundException is
+   *     thrown if no index matched.
+   */
+  @Override
+  public Map<String, IndexMapping> getIndexMappings(String indexExpression) {
+    try {
+      ClusterState state = clusterService.state();
+      String[] concreteIndices = resolveIndexExpression(state, new String[] {indexExpression});
+
+      return populateIndexMappings(
+          state.metaData().findMappings(concreteIndices, ALL_TYPES, ALL_FIELDS));
+    } catch (IOException e) {
+      throw new IllegalStateException(
+          "Failed to read mapping in cluster state for index pattern [" + indexExpression + "]", e);
     }
-
-    @Override
-    public void schedule(Runnable task) {
-        ThreadPool threadPool = client.threadPool();
-        threadPool.schedule(
-            threadPool.preserveContext(withCurrentContext(task)),
-            new TimeValue(0),
-            "search"    //TODO: use search worker pool for now
-        );
-    }
-
-    private String[] resolveIndexExpression(ClusterState state, String[] indices) {
-        return resolver.concreteIndexNames(state, IndicesOptions.strictExpandOpen(), indices);
+  }
+
+  /** TODO: Scroll doesn't work for aggregation. Support aggregation later. */
+  @Override
+  public ElasticsearchResponse search(ElasticsearchRequest request) {
+    SearchResponse esResponse;
+    if (request.isScrollStarted()) {
+      esResponse = client.searchScroll(request.scrollRequest()).actionGet();
+    } else {
+      esResponse = client.search(request.searchRequest()).actionGet();
     }
+    request.setScrollId(esResponse.getScrollId());
 
-    private Map<String, IndexMapping> populateIndexMappings(
-        ImmutableOpenMap<String, ImmutableOpenMap<String, MappingMetaData>> indexMappings) {
+    return new ElasticsearchResponse(esResponse);
+  }
 
-        ImmutableMap.Builder<String, IndexMapping> result = ImmutableMap.builder();
-        for (ObjectObjectCursor<String, ImmutableOpenMap<String, MappingMetaData>> cursor : indexMappings) {
-            result.put(cursor.key, populateIndexMapping(cursor.value));
-        }
-        return result.build();
+  @Override
+  public void cleanup(ElasticsearchRequest request) {
+    if (request.isScrollStarted()) {
+      client.prepareClearScroll().addScrollId(request.getScrollId()).get();
+      request.reset();
     }
-
-    private IndexMapping populateIndexMapping(ImmutableOpenMap<String, MappingMetaData> indexMapping) {
-        if (indexMapping.isEmpty()) {
-            return new IndexMapping(Collections.emptyMap());
-        }
-        return new IndexMapping(indexMapping.iterator().next().value);
+  }
+
+  @Override
+  public void schedule(Runnable task) {
+    ThreadPool threadPool = client.threadPool();
+    threadPool.schedule(
+        threadPool.preserveContext(withCurrentContext(task)),
+        new TimeValue(0),
+        "search" // TODO: use search worker pool for now
+    );
+  }
+
+  private String[] resolveIndexExpression(ClusterState state, String[] indices) {
+    return resolver.concreteIndexNames(state, IndicesOptions.strictExpandOpen(), indices);
+  }
+
+  private Map<String, IndexMapping> populateIndexMappings(
+      ImmutableOpenMap<String, ImmutableOpenMap<String, MappingMetaData>> indexMappings) {
+
+    ImmutableMap.Builder<String, IndexMapping> result = ImmutableMap.builder();
+    for (ObjectObjectCursor<String, ImmutableOpenMap<String, MappingMetaData>> cursor :
+        indexMappings) {
+      result.put(cursor.key, populateIndexMapping(cursor.value));
     }
+    return result.build();
+  }
 
-    /** Copy from LogUtils */
-    private static Runnable withCurrentContext(final Runnable task) {
-        final Map<String, String> currentContext = ThreadContext.getImmutableContext();
-        return () -> {
-            ThreadContext.putAll(currentContext);
-            task.run();
-        };
+  private IndexMapping populateIndexMapping(
+      ImmutableOpenMap<String, MappingMetaData> indexMapping) {
+    if (indexMapping.isEmpty()) {
+      return new IndexMapping(Collections.emptyMap());
     }
-
+    return new IndexMapping(indexMapping.iterator().next().value);
+  }
+
+  /** Copy from LogUtils. */
+  private static Runnable withCurrentContext(final Runnable task) {
+    final Map<String, String> currentContext = ThreadContext.getImmutableContext();
+    return () -> {
+      ThreadContext.putAll(currentContext);
+      task.run();
+    };
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClient.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClient.java
index 2734a51607..ec66dbca75 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClient.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClient.java
@@ -19,6 +19,9 @@
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.mapping.IndexMapping;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.request.ElasticsearchRequest;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
+import java.io.IOException;
+import java.util.Map;
+import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import org.elasticsearch.action.search.ClearScrollRequest;
 import org.elasticsearch.action.search.SearchResponse;
@@ -27,79 +30,67 @@
 import org.elasticsearch.client.indices.GetMappingsRequest;
 import org.elasticsearch.client.indices.GetMappingsResponse;
 
-import java.io.IOException;
-import java.util.Map;
-import java.util.stream.Collectors;
-
 /**
  * Elasticsearch REST client to support standalone mode that runs entire engine from remote.
  *
- * TODO: Support for authN and authZ with AWS Sigv4 or security plugin.
+ * <p>TODO: Support for authN and authZ with AWS Sigv4 or security plugin.
  */
 @RequiredArgsConstructor
 public class ElasticsearchRestClient implements ElasticsearchClient {
 
-    /**
-     * Elasticsearch high level REST client
-     */
-    private final RestHighLevelClient client;
-
+  /** Elasticsearch high level REST client. */
+  private final RestHighLevelClient client;
 
-    @Override
-    public Map<String, IndexMapping> getIndexMappings(String indexExpression) {
-        GetMappingsRequest request = new GetMappingsRequest().indices(indexExpression);
-        try {
-            GetMappingsResponse response = client.indices().getMapping(request, RequestOptions.DEFAULT);
-            return response.mappings().entrySet().stream().
-                            collect(Collectors.toMap(
-                                Map.Entry::getKey,
-                                e -> new IndexMapping(e.getValue()))
-                            );
-        } catch (IOException e) {
-            throw new IllegalStateException(
-                "Failed to get index mappings for " + indexExpression, e);
-        }
+  @Override
+  public Map<String, IndexMapping> getIndexMappings(String indexExpression) {
+    GetMappingsRequest request = new GetMappingsRequest().indices(indexExpression);
+    try {
+      GetMappingsResponse response = client.indices().getMapping(request, RequestOptions.DEFAULT);
+      return response.mappings().entrySet().stream()
+          .collect(Collectors.toMap(Map.Entry::getKey, e -> new IndexMapping(e.getValue())));
+    } catch (IOException e) {
+      throw new IllegalStateException("Failed to get index mappings for " + indexExpression, e);
     }
+  }
 
-    @Override
-    public ElasticsearchResponse search(ElasticsearchRequest request) {
-        try {
-            SearchResponse esResponse;
-            if (request.isScrollStarted()) {
-                esResponse = client.scroll(request.scrollRequest(), RequestOptions.DEFAULT);
-            } else {
-                esResponse = client.search(request.searchRequest(), RequestOptions.DEFAULT);
-            }
-            request.setScrollId(esResponse.getScrollId());
+  @Override
+  public ElasticsearchResponse search(ElasticsearchRequest request) {
+    try {
+      SearchResponse esResponse;
+      if (request.isScrollStarted()) {
+        esResponse = client.scroll(request.scrollRequest(), RequestOptions.DEFAULT);
+      } else {
+        esResponse = client.search(request.searchRequest(), RequestOptions.DEFAULT);
+      }
+      request.setScrollId(esResponse.getScrollId());
 
-            return new ElasticsearchResponse(esResponse);
-        } catch (IOException e) {
-            throw new IllegalStateException(
-                "Failed to perform search operation with request " + request, e);
-        }
+      return new ElasticsearchResponse(esResponse);
+    } catch (IOException e) {
+      throw new IllegalStateException(
+          "Failed to perform search operation with request " + request, e);
     }
+  }
 
-    @Override
-    public void cleanup(ElasticsearchRequest request) {
-        try {
-            if (!request.isScrollStarted()) {
-                return;
-            }
-
-            ClearScrollRequest clearRequest = new ClearScrollRequest();
-            clearRequest.addScrollId(request.getScrollId());
-            client.clearScroll(clearRequest, RequestOptions.DEFAULT);
-        } catch (IOException e) {
-            throw new IllegalStateException(
-                "Failed to clean up resources for search request " + request, e);
-        } finally {
-            request.reset();
-        }
-    }
+  @Override
+  public void cleanup(ElasticsearchRequest request) {
+    try {
+      if (!request.isScrollStarted()) {
+        return;
+      }
 
-    @Override
-    public void schedule(Runnable task) {
-        task.run();
+      ClearScrollRequest clearRequest = new ClearScrollRequest();
+      clearRequest.addScrollId(request.getScrollId());
+      client.clearScroll(clearRequest, RequestOptions.DEFAULT);
+    } catch (IOException e) {
+      throw new IllegalStateException(
+          "Failed to clean up resources for search request " + request, e);
+    } finally {
+      request.reset();
     }
+  }
 
+  @Override
+  public void schedule(Runnable task) {
+    task.run();
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngine.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngine.java
index 308b742b3c..21fc2b467a 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngine.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngine.java
@@ -21,38 +21,35 @@
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchClient;
 import com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
-import lombok.RequiredArgsConstructor;
-
 import java.util.ArrayList;
 import java.util.List;
+import lombok.RequiredArgsConstructor;
 
-/**
- * Elasticsearch execution engine implementation.
- */
+/** Elasticsearch execution engine implementation. */
 @RequiredArgsConstructor
 public class ElasticsearchExecutionEngine implements ExecutionEngine {
 
-    private final ElasticsearchClient client;
+  private final ElasticsearchClient client;
 
-    @Override
-    public void execute(PhysicalPlan plan, ResponseListener<QueryResponse> listener) {
-        client.schedule(() -> {
-            try {
-                List<ExprValue> result = new ArrayList<>();
-                plan.open();
+  @Override
+  public void execute(PhysicalPlan plan, ResponseListener<QueryResponse> listener) {
+    client.schedule(
+        () -> {
+          try {
+            List<ExprValue> result = new ArrayList<>();
+            plan.open();
 
-                while (plan.hasNext()) {
-                    result.add(plan.next());
-                }
-
-                QueryResponse response = new QueryResponse(result);
-                listener.onResponse(response);
-            } catch (Exception e) {
-                listener.onFailure(e);
-            } finally {
-                plan.close();
+            while (plan.hasNext()) {
+              result.add(plan.next());
             }
-        });
-    }
 
+            QueryResponse response = new QueryResponse(result);
+            listener.onResponse(response);
+          } catch (Exception e) {
+            listener.onFailure(e);
+          } finally {
+            plan.close();
+          }
+        });
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMapping.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMapping.java
index d09f6b35c4..1f986919c9 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMapping.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMapping.java
@@ -16,16 +16,15 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.mapping;
 
-import com.google.common.collect.ImmutableMap;
-import lombok.ToString;
-import org.elasticsearch.cluster.metadata.MappingMetaData;
+import static java.util.Collections.emptyMap;
 
+import com.google.common.collect.ImmutableMap;
 import java.util.Map;
 import java.util.function.BiConsumer;
 import java.util.function.Function;
 import java.util.stream.Collectors;
-
-import static java.util.Collections.emptyMap;
+import lombok.ToString;
+import org.elasticsearch.cluster.metadata.MappingMetaData;
 
 /**
  * Elasticsearch index mapping. Because there is no specific behavior for different field types,
@@ -34,91 +33,81 @@
 @ToString
 public class IndexMapping {
 
-    /**
-     * Field mappings from field name to field type in Elasticsearch date type system.
-     */
-    private final Map<String, String> fieldMappings;
-
-    public IndexMapping(Map<String, String> fieldMappings) {
-        this.fieldMappings = fieldMappings;
-    }
-
-    public IndexMapping(MappingMetaData metaData) {
-        this.fieldMappings = flatMappings(metaData.getSourceAsMap());
-    }
-
-    /**
-     * How many fields in the index (after flatten)
-     * @return  field size
-     */
-    public int size() {
-        return fieldMappings.size();
-    }
-
-    /**
-     * Return field type by its name.
-     * @param fieldName     field name
-     * @return              field type in string. Or null if not exist.
-     */
-    public String getFieldType(String fieldName) {
-        return fieldMappings.get(fieldName);
-    }
-
-    /**
-     * Get all field types and transform raw string type to expected type.
-     * @param transform     transform function to transform field type in string to another type
-     * @param <Type>        expected field type class
-     * @return              mapping from field name to field type
-     */
-    public <Type> Map<String, Type> getAllFieldTypes(Function<String, Type> transform) {
-        return fieldMappings.entrySet().
-                             stream().
-                             collect(Collectors.toMap(
-                                 Map.Entry::getKey,
-                                 e -> transform.apply(e.getValue())
-                             ));
-    }
-
-    @SuppressWarnings("unchecked")
-    private Map<String, String> flatMappings(Map<String, Object> indexMapping) {
-        ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
-
-        flatMappings(
-            ((Map<String, Object>) indexMapping.getOrDefault("properties", emptyMap())),
-            "",
-            builder::put
-        );
-        return builder.build();
-    }
-
-    @SuppressWarnings("unchecked")
-    private void flatMappings(Map<String, Object> mappings,
-                              String path,
-                              BiConsumer<String, String> func) {
-        mappings.forEach(
-            (fieldName, mappingObject) -> {
-                Map<String, Object> mapping = (Map<String, Object>) mappingObject;
-                String fullFieldName = path.isEmpty() ? fieldName : path + "." + fieldName;
-                String type = (String) mapping.getOrDefault("type", "object");
-                func.accept(fullFieldName, type);
-
-                if (mapping.containsKey("fields")) { // Multi-field
-                    ((Map<String, Map<String, Object>>) mapping.get("fields")).forEach(
-                        (innerFieldName, innerMapping) ->
-                            func.accept(fullFieldName + "." + innerFieldName,
-                                (String) innerMapping.getOrDefault("type", "object"))
-                    );
-                }
-
-                if (mapping.containsKey("properties")) { // Nested field
-                    flatMappings(
-                        (Map<String, Object>) mapping.get("properties"),
-                        fullFieldName,
-                        func
-                    );
-                }
-            }
-        );
-    }
-
+  /** Field mappings from field name to field type in Elasticsearch date type system. */
+  private final Map<String, String> fieldMappings;
+
+  public IndexMapping(Map<String, String> fieldMappings) {
+    this.fieldMappings = fieldMappings;
+  }
+
+  public IndexMapping(MappingMetaData metaData) {
+    this.fieldMappings = flatMappings(metaData.getSourceAsMap());
+  }
+
+  /**
+   * How many fields in the index (after flatten).
+   *
+   * @return field size
+   */
+  public int size() {
+    return fieldMappings.size();
+  }
+
+  /**
+   * Return field type by its name.
+   *
+   * @param fieldName field name
+   * @return field type in string. Or null if not exist.
+   */
+  public String getFieldType(String fieldName) {
+    return fieldMappings.get(fieldName);
+  }
+
+  /**
+   * Get all field types and transform raw string type to expected type.
+   *
+   * @param transform transform function to transform field type in string to another type
+   * @param <T> expected field type class
+   * @return mapping from field name to field type
+   */
+  public <T> Map<String, T> getAllFieldTypes(Function<String, T> transform) {
+    return fieldMappings.entrySet().stream()
+        .collect(Collectors.toMap(Map.Entry::getKey, e -> transform.apply(e.getValue())));
+  }
+
+  @SuppressWarnings("unchecked")
+  private Map<String, String> flatMappings(Map<String, Object> indexMapping) {
+    ImmutableMap.Builder<String, String> builder = new ImmutableMap.Builder<>();
+
+    flatMappings(
+        ((Map<String, Object>) indexMapping.getOrDefault("properties", emptyMap())),
+        "",
+        builder::put);
+    return builder.build();
+  }
+
+  @SuppressWarnings("unchecked")
+  private void flatMappings(
+      Map<String, Object> mappings, String path, BiConsumer<String, String> func) {
+    mappings.forEach(
+        (fieldName, mappingObject) -> {
+          Map<String, Object> mapping = (Map<String, Object>) mappingObject;
+          String fullFieldName = path.isEmpty() ? fieldName : path + "." + fieldName;
+          String type = (String) mapping.getOrDefault("type", "object");
+          func.accept(fullFieldName, type);
+
+          if (mapping.containsKey("fields")) { // Multi-field
+            ((Map<String, Map<String, Object>>) mapping.get("fields"))
+                .forEach(
+                    (innerFieldName, innerMapping) ->
+                        func.accept(
+                            fullFieldName + "." + innerFieldName,
+                            (String) innerMapping.getOrDefault("type", "object")));
+          }
+
+          if (mapping.containsKey("properties")) { // Nested field
+            flatMappings((Map<String, Object>) mapping.get("properties"), fullFieldName, func);
+          }
+        });
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequest.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequest.java
index f49d2e6e35..7f2a151044 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequest.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequest.java
@@ -16,6 +16,7 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.request;
 
+import java.util.Objects;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
@@ -26,13 +27,11 @@
 import org.elasticsearch.common.unit.TimeValue;
 import org.elasticsearch.search.builder.SearchSourceBuilder;
 
-import java.util.Objects;
-
 /**
  * Elasticsearch search request. This has to be stateful because it needs to:
  *
- *  1) Accumulate search source builder when visiting logical plan to push down operation
- *  2) Maintain scroll ID between calls to client search method
+ * <p>1) Accumulate search source builder when visiting logical plan to push down operation 2)
+ * Maintain scroll ID between calls to client search method
  */
 @EqualsAndHashCode
 @RequiredArgsConstructor
@@ -40,62 +39,57 @@
 @ToString
 public class ElasticsearchRequest {
 
-    /**
-     * Default scroll context timeout in minutes
-     */
-    public static final TimeValue DEFAULT_SCROLL_TIMEOUT = TimeValue.timeValueMinutes(1L);
-
-    /**
-     * Index name.
-     */
-    private final String indexName;
+  /** Default scroll context timeout in minutes. */
+  public static final TimeValue DEFAULT_SCROLL_TIMEOUT = TimeValue.timeValueMinutes(1L);
 
-    /**
-     * Scroll id which is set after first request issued.
-     * Because ElasticsearchClient is shared by multi-thread so this state has to be maintained here.
-     */
-    @Setter
-    private String scrollId;
+  /** Index name. */
+  private final String indexName;
 
-    /**
-     * Search request source builder.
-     */
-    private final SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
+  /**
+   * Scroll id which is set after first request issued. Because ElasticsearchClient is shared by
+   * multi-thread so this state has to be maintained here.
+   */
+  @Setter private String scrollId;
 
-    /**
-     * Generate Elasticsearch search request.
-     * @return  search request
-     */
-    public SearchRequest searchRequest() {
-        return new SearchRequest().indices(indexName).
-                                   scroll(DEFAULT_SCROLL_TIMEOUT).
-                                   source(sourceBuilder);
-    }
+  /** Search request source builder. */
+  private final SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
 
-    /**
-     * Is scroll started which means pages after first is being requested
-     * @return  true if scroll started
-     */
-    public boolean isScrollStarted() {
-        return (scrollId != null);
-    }
+  /**
+   * Generate Elasticsearch search request.
+   *
+   * @return search request
+   */
+  public SearchRequest searchRequest() {
+    return new SearchRequest()
+        .indices(indexName)
+        .scroll(DEFAULT_SCROLL_TIMEOUT)
+        .source(sourceBuilder);
+  }
 
-    /**
-     * Generate Elasticsearch scroll request by scroll id maintained.
-     * @return  scroll request
-     */
-    public SearchScrollRequest scrollRequest() {
-        Objects.requireNonNull(scrollId, "Scroll id cannot be null");
-        return new SearchScrollRequest().scroll(DEFAULT_SCROLL_TIMEOUT).
-                                         scrollId(scrollId);
-    }
+  /**
+   * Is scroll started which means pages after first is being requested.
+   *
+   * @return true if scroll started
+   */
+  public boolean isScrollStarted() {
+    return (scrollId != null);
+  }
 
-    /**
-     * Reset internal state in case any stale data. However, ideally the same instance
-     * is not supposed to be reused across different physical plan.
-     */
-    public void reset() {
-        scrollId = null;
-    }
+  /**
+   * Generate Elasticsearch scroll request by scroll id maintained.
+   *
+   * @return scroll request
+   */
+  public SearchScrollRequest scrollRequest() {
+    Objects.requireNonNull(scrollId, "Scroll id cannot be null");
+    return new SearchScrollRequest().scroll(DEFAULT_SCROLL_TIMEOUT).scrollId(scrollId);
+  }
 
+  /**
+   * Reset internal state in case any stale data. However, ideally the same instance is not supposed
+   * to be reused across different physical plan.
+   */
+  public void reset() {
+    scrollId = null;
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponse.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponse.java
index ae94eede4c..e3382799ff 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponse.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponse.java
@@ -16,47 +16,42 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.response;
 
+import java.util.Iterator;
 import lombok.EqualsAndHashCode;
 import lombok.ToString;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.search.SearchHit;
 import org.elasticsearch.search.SearchHits;
 
-import java.util.Iterator;
-
-/**
- * Elasticsearch search response
- */
+/** Elasticsearch search response. */
 @EqualsAndHashCode
 @ToString
 public class ElasticsearchResponse implements Iterable<SearchHit> {
 
-    /**
-     * Search query result (non-aggregation)
-     */
-    private final SearchHits hits;
-
-
-    public ElasticsearchResponse(SearchResponse esResponse) {
-        this.hits = esResponse.getHits(); //TODO: aggregation result is separate and not in SearchHit[]
-    }
-
-    /**
-     * Is response empty. As ES doc says, "Each call to the scroll API returns the next batch of results
-     * until there are no more results left to return, ie the hits array is empty."
-     * @return  true for empty
-     */
-    public boolean isEmpty() {
-        return (hits.getHits() == null) || (hits.getHits().length == 0);
-    }
-
-    /**
-     * Make response iterable without need to return internal data structure explicitly.
-     * @return  search hit iterator
-     */
-    @Override
-    public Iterator<SearchHit> iterator() {
-        return hits.iterator();
-    }
-
+  /** Search query result (non-aggregation). */
+  private final SearchHits hits;
+
+  public ElasticsearchResponse(SearchResponse esResponse) {
+    this.hits = esResponse.getHits(); // TODO: aggregation result is separate and not in SearchHit[]
+  }
+
+  /**
+   * Is response empty. As ES doc says, "Each call to the scroll API returns the next batch of
+   * results until there are no more results left to return, ie the hits array is empty."
+   *
+   * @return true for empty
+   */
+  public boolean isEmpty() {
+    return (hits.getHits() == null) || (hits.getHits().length == 0);
+  }
+
+  /**
+   * Make response iterable without need to return internal data structure explicitly.
+   *
+   * @return search hit iterator
+   */
+  @Override
+  public Iterator<SearchHit> iterator() {
+    return hits.iterator();
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/security/SecurityAccess.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/security/SecurityAccess.java
index f1c7d5e8dc..f42d100393 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/security/SecurityAccess.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/security/SecurityAccess.java
@@ -15,24 +15,28 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.security;
 
-import org.elasticsearch.SpecialPermission;
-
 import java.io.IOException;
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.security.PrivilegedExceptionAction;
+import org.elasticsearch.SpecialPermission;
 
 /**
- * Ref: https://www.elastic.co/guide/en/elasticsearch/plugins/current/plugin-authors.html#_java_security_permissions
+ * Ref:
+ * https://www.elastic.co/guide/en/elasticsearch/plugins/current/plugin-authors.html#_java_security_permissions
  */
 public class SecurityAccess {
-    
-    public static <T> T doPrivileged(final PrivilegedExceptionAction<T> operation) throws IOException {
-        SpecialPermission.check();
-        try {
-            return AccessController.doPrivileged(operation);
-        } catch (final PrivilegedActionException e) {
-            throw (IOException) e.getCause();
-        }
+
+  /**
+   * Execute the operation in privileged mode.
+   */
+  public static <T> T doPrivileged(final PrivilegedExceptionAction<T> operation)
+      throws IOException {
+    SpecialPermission.check();
+    try {
+      return AccessController.doPrivileged(operation);
+    } catch (final PrivilegedActionException e) {
+      throw (IOException) e.getCause();
     }
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndex.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndex.java
index 569b78fa79..2faeaf66c0 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndex.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndex.java
@@ -41,125 +41,125 @@
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.SortOperator;
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import com.google.common.collect.ImmutableMap;
-import lombok.RequiredArgsConstructor;
-
 import java.util.HashMap;
 import java.util.Map;
+import lombok.RequiredArgsConstructor;
 
-/**
- * Elasticsearch table (index) implementation.
- */
+/** Elasticsearch table (index) implementation. */
 @RequiredArgsConstructor
 public class ElasticsearchIndex implements Table {
 
-    /**
-     * Type mapping from Elasticsearch data type to expression type in our type system in query engine.
-     * TODO: date, geo, ip etc.
-     */
-    private final static Map<String, ExprType> ES_TYPE_TO_EXPR_TYPE_MAPPING =
-        ImmutableMap.<String, ExprType>builder().put("text", ExprType.STRING).
-                                                 put("keyword", ExprType.STRING).
-                                                 put("integer", ExprType.INTEGER).
-                                                 put("long", ExprType.LONG).
-                                                 put("float", ExprType.FLOAT).
-                                                 put("double", ExprType.DOUBLE).
-                                                 put("boolean", ExprType.BOOLEAN).
-                                                 put("nested", ExprType.ARRAY).
-                                                 put("object", ExprType.STRUCT).
-                                                 build();
-
-    /**
-     * Elasticsearch client connection.
-     */
-    private final ElasticsearchClient client;
-
-    /**
-     * Current Elasticsearch index name.
-     */
-    private final String indexName;
-
-
-    /*
-     * TODO: Assume indexName doesn't have wildcard.
-     *  Need to either handle field name conflicts
-     *   or lazy evaluate when query engine pulls field type.
-     */
-    @Override
-    public Map<String, ExprType> getFieldTypes() {
-        Map<String, ExprType> fieldTypes = new HashMap<>();
-        Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
-        for (IndexMapping indexMapping : indexMappings.values()) {
-            fieldTypes.putAll(indexMapping.getAllFieldTypes(this::transformESTypeToExprType));
-        }
-        return fieldTypes;
+  /**
+   * Type mapping from Elasticsearch data type to expression type in our type system in query
+   * engine. TODO: date, geo, ip etc.
+   */
+  private static final Map<String, ExprType> ES_TYPE_TO_EXPR_TYPE_MAPPING =
+      ImmutableMap.<String, ExprType>builder()
+          .put("text", ExprType.STRING)
+          .put("keyword", ExprType.STRING)
+          .put("integer", ExprType.INTEGER)
+          .put("long", ExprType.LONG)
+          .put("float", ExprType.FLOAT)
+          .put("double", ExprType.DOUBLE)
+          .put("boolean", ExprType.BOOLEAN)
+          .put("nested", ExprType.ARRAY)
+          .put("object", ExprType.STRUCT)
+          .build();
+
+  /** Elasticsearch client connection. */
+  private final ElasticsearchClient client;
+
+  /** Current Elasticsearch index name. */
+  private final String indexName;
+
+  /*
+   * TODO: Assume indexName doesn't have wildcard.
+   *  Need to either handle field name conflicts
+   *   or lazy evaluate when query engine pulls field type.
+   */
+  @Override
+  public Map<String, ExprType> getFieldTypes() {
+    Map<String, ExprType> fieldTypes = new HashMap<>();
+    Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
+    for (IndexMapping indexMapping : indexMappings.values()) {
+      fieldTypes.putAll(indexMapping.getAllFieldTypes(this::transformESTypeToExprType));
     }
+    return fieldTypes;
+  }
+
+  /** TODO: Push down operations to index scan operator as much as possible in future. */
+  @Override
+  public PhysicalPlan implement(LogicalPlan plan) {
+    ElasticsearchIndexScan indexScan = new ElasticsearchIndexScan(client, indexName);
 
     /**
-     * TODO: Push down operations to index scan operator as much as possible in future.
+     * Visit logical plan with index scan as context so logical operators visited, such as
+     * aggregation, filter, will accumulate (push down) Elasticsearch query and aggregation DSL on
+     * index scan.
      */
-    @Override
-    public PhysicalPlan implement(LogicalPlan plan) {
-        ElasticsearchIndexScan indexScan = new ElasticsearchIndexScan(client, indexName);
-
-        /*
-         * Visit logical plan with index scan as context so logical operators visited, such as aggregation, filter,
-         * will accumulate (push down) Elasticsearch query and aggregation DSL on index scan.
-         */
-        return plan.accept(new LogicalPlanNodeVisitor<PhysicalPlan, ElasticsearchIndexScan>() {
-            @Override
-            public PhysicalPlan visitDedupe(LogicalDedupe node, ElasticsearchIndexScan context) {
-                return new DedupeOperator(visitChild(node, context), node.getDedupeList(),
-                    node.getAllowedDuplication(), node.getKeepEmpty(), node.getConsecutive());
-            }
-
-            @Override
-            public PhysicalPlan visitProject(LogicalProject node, ElasticsearchIndexScan context) {
-                return new ProjectOperator(visitChild(node, context), node.getProjectList());
-            }
-
-            @Override
-            public PhysicalPlan visitRemove(LogicalRemove node, ElasticsearchIndexScan context) {
-                return new RemoveOperator(visitChild(node, context), node.getRemoveList());
-            }
-
-            @Override
-            public PhysicalPlan visitEval(LogicalEval node, ElasticsearchIndexScan context) {
-                return new EvalOperator(visitChild(node, context), node.getExpressions());
-            }
-
-            @Override
-            public PhysicalPlan visitSort(LogicalSort node, ElasticsearchIndexScan context) {
-                return new SortOperator(visitChild(node, context), node.getCount(), node.getSortList());
-            }
-
-            @Override
-            public PhysicalPlan visitRename(LogicalRename node, ElasticsearchIndexScan context) {
-                return new RenameOperator(visitChild(node, context), node.getRenameMap());
-            }
-
-            @Override
-            public PhysicalPlan visitAggregation(LogicalAggregation node, ElasticsearchIndexScan context) {
-                return new AggregationOperator(visitChild(node, context), node.getAggregatorList(), node.getGroupByList());
-            }
-
-            @Override
-            public PhysicalPlan visitFilter(LogicalFilter node, ElasticsearchIndexScan context) {
-                return new FilterOperator(visitChild(node, context), node.getCondition());
-            }
-
-            @Override
-            public PhysicalPlan visitRelation(LogicalRelation node, ElasticsearchIndexScan context) {
-                return indexScan;
-            }
-
-            private PhysicalPlan visitChild(LogicalPlan node, ElasticsearchIndexScan context) {
-                // Logical operators visited here can only have single child.
-                return node.getChild().get(0).accept(this, context);
-            }
-        }, indexScan);
-    }
-
-    private ExprType transformESTypeToExprType(String esType) {
-        return ES_TYPE_TO_EXPR_TYPE_MAPPING.getOrDefault(esType, ExprType.UNKNOWN);
-    }
+    return plan.accept(
+        new LogicalPlanNodeVisitor<PhysicalPlan, ElasticsearchIndexScan>() {
+          @Override
+          public PhysicalPlan visitDedupe(LogicalDedupe node, ElasticsearchIndexScan context) {
+            return new DedupeOperator(
+                visitChild(node, context),
+                node.getDedupeList(),
+                node.getAllowedDuplication(),
+                node.getKeepEmpty(),
+                node.getConsecutive());
+          }
+
+          @Override
+          public PhysicalPlan visitProject(LogicalProject node, ElasticsearchIndexScan context) {
+            return new ProjectOperator(visitChild(node, context), node.getProjectList());
+          }
+
+          @Override
+          public PhysicalPlan visitRemove(LogicalRemove node, ElasticsearchIndexScan context) {
+            return new RemoveOperator(visitChild(node, context), node.getRemoveList());
+          }
+
+          @Override
+          public PhysicalPlan visitEval(LogicalEval node, ElasticsearchIndexScan context) {
+            return new EvalOperator(visitChild(node, context), node.getExpressions());
+          }
+
+          @Override
+          public PhysicalPlan visitSort(LogicalSort node, ElasticsearchIndexScan context) {
+            return new SortOperator(visitChild(node, context), node.getCount(), node.getSortList());
+          }
+
+          @Override
+          public PhysicalPlan visitRename(LogicalRename node, ElasticsearchIndexScan context) {
+            return new RenameOperator(visitChild(node, context), node.getRenameMap());
+          }
+
+          @Override
+          public PhysicalPlan visitAggregation(
+              LogicalAggregation node, ElasticsearchIndexScan context) {
+            return new AggregationOperator(
+                visitChild(node, context), node.getAggregatorList(), node.getGroupByList());
+          }
+
+          @Override
+          public PhysicalPlan visitFilter(LogicalFilter node, ElasticsearchIndexScan context) {
+            return new FilterOperator(visitChild(node, context), node.getCondition());
+          }
+
+          @Override
+          public PhysicalPlan visitRelation(LogicalRelation node, ElasticsearchIndexScan context) {
+            return indexScan;
+          }
+
+          private PhysicalPlan visitChild(LogicalPlan node, ElasticsearchIndexScan context) {
+            // Logical operators visited here can only have single child.
+            return node.getChild().get(0).accept(this, context);
+          }
+        },
+        indexScan);
+  }
+
+  private ExprType transformESTypeToExprType(String esType) {
+    return ES_TYPE_TO_EXPR_TYPE_MAPPING.getOrDefault(esType, ExprType.UNKNOWN);
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScan.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScan.java
index dcda5914c7..e261782700 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScan.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScan.java
@@ -23,73 +23,60 @@
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
 import com.amazon.opendistroforelasticsearch.sql.storage.TableScanOperator;
 import com.google.common.collect.Iterables;
-import lombok.EqualsAndHashCode;
-import lombok.ToString;
-import org.elasticsearch.search.SearchHit;
-
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+import org.elasticsearch.search.SearchHit;
 
-/**
- * Elasticsearch index scan operator
- */
+/** Elasticsearch index scan operator. */
 @EqualsAndHashCode(onlyExplicitlyIncluded = true, callSuper = false)
 @ToString(onlyExplicitlyIncluded = true)
 public class ElasticsearchIndexScan extends TableScanOperator {
 
-    /**
-     * Elasticsearch client.
-     */
-    private final ElasticsearchClient client;
-
-    /**
-     * Search request.
-     */
-    @EqualsAndHashCode.Include
-    @ToString.Include
-    private final ElasticsearchRequest request;
+  /** Elasticsearch client. */
+  private final ElasticsearchClient client;
 
-    /**
-     * Search response for current batch.
-     */
-    private Iterator<SearchHit> hits;
+  /** Search request. */
+  @EqualsAndHashCode.Include @ToString.Include private final ElasticsearchRequest request;
 
+  /** Search response for current batch. */
+  private Iterator<SearchHit> hits;
 
-    public ElasticsearchIndexScan(ElasticsearchClient client, String indexName) {
-        this.client = client;
-        this.request = new ElasticsearchRequest(indexName);
-    }
+  public ElasticsearchIndexScan(ElasticsearchClient client, String indexName) {
+    this.client = client;
+    this.request = new ElasticsearchRequest(indexName);
+  }
 
-    @Override
-    public void open() {
-        super.open();
+  @Override
+  public void open() {
+    super.open();
 
-        // For now pull all results immediately once open
-        List<ElasticsearchResponse> responses = new ArrayList<>();
-        ElasticsearchResponse response = client.search(request);
-        while (!response.isEmpty()) {
-            responses.add(response);
-            response = client.search(request);
-        }
-        hits = Iterables.concat(responses.toArray(new ElasticsearchResponse[0])).iterator();
+    // For now pull all results immediately once open
+    List<ElasticsearchResponse> responses = new ArrayList<>();
+    ElasticsearchResponse response = client.search(request);
+    while (!response.isEmpty()) {
+      responses.add(response);
+      response = client.search(request);
     }
+    hits = Iterables.concat(responses.toArray(new ElasticsearchResponse[0])).iterator();
+  }
 
-    @Override
-    public boolean hasNext() {
-        return hits.hasNext();
-    }
+  @Override
+  public boolean hasNext() {
+    return hits.hasNext();
+  }
 
-    @Override
-    public ExprValue next() {
-        return ExprValueUtils.fromObjectValue(hits.next().getSourceAsMap());
-    }
-
-    @Override
-    public void close() {
-        super.close();
+  @Override
+  public ExprValue next() {
+    return ExprValueUtils.fromObjectValue(hits.next().getSourceAsMap());
+  }
 
-        client.cleanup(request);
-    }
+  @Override
+  public void close() {
+    super.close();
 
+    client.cleanup(request);
+  }
 }
diff --git a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngine.java b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngine.java
index 4d493d77e5..181d55db9c 100644
--- a/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngine.java
+++ b/elasticsearch/src/main/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngine.java
@@ -21,20 +21,15 @@
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import lombok.RequiredArgsConstructor;
 
-/**
- * Elasticsearch storage engine implementation
- */
+/** Elasticsearch storage engine implementation. */
 @RequiredArgsConstructor
 public class ElasticsearchStorageEngine implements StorageEngine {
 
-    /**
-     * Elasticsearch client connection
-     */
-    private final ElasticsearchClient client;
-
-    @Override
-    public Table getTable(String name) {
-        return new ElasticsearchIndex(client, name);
-    }
+  /** Elasticsearch client connection. */
+  private final ElasticsearchClient client;
 
+  @Override
+  public Table getTable(String name) {
+    return new ElasticsearchIndex(client, name);
+  }
 }
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClientTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClientTest.java
index 51af3225ba..6a23a9476c 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClientTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchNodeClientTest.java
@@ -16,12 +16,29 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.client;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Answers.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.mapping.IndexMapping;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.request.ElasticsearchRequest;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
 import com.google.common.base.Charsets;
 import com.google.common.collect.ImmutableSortedMap;
 import com.google.common.io.Resources;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.lucene.search.TotalHits;
 import org.elasticsearch.action.search.ClearScrollRequestBuilder;
 import org.elasticsearch.action.search.SearchResponse;
@@ -48,250 +65,239 @@
 import org.mockito.Mockito;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import java.io.IOException;
-import java.net.URL;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.Answers.RETURNS_DEEP_STUBS;
-import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.doAnswer;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchNodeClientTest {
 
-    private static final String TEST_MAPPING_FILE = "mappings/accounts.json";
-
-    @Mock(answer = RETURNS_DEEP_STUBS)
-    private NodeClient nodeClient;
-
-    @Test
-    public void getIndexMappings() throws IOException {
-        URL url = Resources.getResource(TEST_MAPPING_FILE);
-        String mappings = Resources.toString(url, Charsets.UTF_8);
-        String indexName = "test";
-        ElasticsearchNodeClient client = mockClient(indexName, mappings);
-
-        Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
-        assertEquals(1, indexMappings.size());
-
-        IndexMapping indexMapping = indexMappings.values().iterator().next();
-        assertEquals(20, indexMapping.size());
-        assertEquals("text", indexMapping.getFieldType("address"));
-        assertEquals("integer", indexMapping.getFieldType("age"));
-        assertEquals("double", indexMapping.getFieldType("balance"));
-        assertEquals("keyword", indexMapping.getFieldType("city"));
-        assertEquals("date", indexMapping.getFieldType("birthday"));
-        assertEquals("geo_point", indexMapping.getFieldType("location"));
-        assertEquals("some_new_es_type_outside_type_system", indexMapping.getFieldType("new_field"));
-        assertEquals("text", indexMapping.getFieldType("field with spaces"));
-        assertEquals("text", indexMapping.getFieldType("employer"));
-        assertEquals("keyword", indexMapping.getFieldType("employer.raw"));
-        assertEquals("nested", indexMapping.getFieldType("projects"));
-        assertEquals("boolean", indexMapping.getFieldType("projects.active"));
-        assertEquals("date", indexMapping.getFieldType("projects.release"));
-        assertEquals("nested", indexMapping.getFieldType("projects.members"));
-        assertEquals("text", indexMapping.getFieldType("projects.members.name"));
-        assertEquals("object", indexMapping.getFieldType("manager"));
-        assertEquals("text", indexMapping.getFieldType("manager.name"));
-        assertEquals("keyword", indexMapping.getFieldType("manager.name.keyword"));
-        assertEquals("keyword", indexMapping.getFieldType("manager.address"));
-        assertEquals("long", indexMapping.getFieldType("manager.salary"));
+  private static final String TEST_MAPPING_FILE = "mappings/accounts.json";
+
+  @Mock(answer = RETURNS_DEEP_STUBS)
+  private NodeClient nodeClient;
+
+  @Test
+  public void getIndexMappings() throws IOException {
+    URL url = Resources.getResource(TEST_MAPPING_FILE);
+    String mappings = Resources.toString(url, Charsets.UTF_8);
+    String indexName = "test";
+    ElasticsearchNodeClient client = mockClient(indexName, mappings);
+
+    Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
+    assertEquals(1, indexMappings.size());
+
+    IndexMapping indexMapping = indexMappings.values().iterator().next();
+    assertEquals(20, indexMapping.size());
+    assertEquals("text", indexMapping.getFieldType("address"));
+    assertEquals("integer", indexMapping.getFieldType("age"));
+    assertEquals("double", indexMapping.getFieldType("balance"));
+    assertEquals("keyword", indexMapping.getFieldType("city"));
+    assertEquals("date", indexMapping.getFieldType("birthday"));
+    assertEquals("geo_point", indexMapping.getFieldType("location"));
+    assertEquals("some_new_es_type_outside_type_system", indexMapping.getFieldType("new_field"));
+    assertEquals("text", indexMapping.getFieldType("field with spaces"));
+    assertEquals("text", indexMapping.getFieldType("employer"));
+    assertEquals("keyword", indexMapping.getFieldType("employer.raw"));
+    assertEquals("nested", indexMapping.getFieldType("projects"));
+    assertEquals("boolean", indexMapping.getFieldType("projects.active"));
+    assertEquals("date", indexMapping.getFieldType("projects.release"));
+    assertEquals("nested", indexMapping.getFieldType("projects.members"));
+    assertEquals("text", indexMapping.getFieldType("projects.members.name"));
+    assertEquals("object", indexMapping.getFieldType("manager"));
+    assertEquals("text", indexMapping.getFieldType("manager.name"));
+    assertEquals("keyword", indexMapping.getFieldType("manager.name.keyword"));
+    assertEquals("keyword", indexMapping.getFieldType("manager.address"));
+    assertEquals("long", indexMapping.getFieldType("manager.salary"));
+  }
+
+  @Test
+  public void getIndexMappingsWithEmptyMapping() {
+    String indexName = "test";
+    ElasticsearchNodeClient client = mockClient(indexName, "");
+    Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
+    assertEquals(1, indexMappings.size());
+
+    IndexMapping indexMapping = indexMappings.values().iterator().next();
+    assertEquals(0, indexMapping.size());
+  }
+
+  @Test
+  public void getIndexMappingsWithIOException() {
+    String indexName = "test";
+    ClusterService clusterService = mockClusterService(indexName, new IOException());
+    ElasticsearchNodeClient client = new ElasticsearchNodeClient(clusterService, nodeClient);
+
+    assertThrows(IllegalStateException.class, () -> client.getIndexMappings(indexName));
+  }
+
+  @Test
+  public void getIndexMappingsWithNonExistIndex() {
+    ElasticsearchNodeClient client =
+        new ElasticsearchNodeClient(mockClusterService("test"), nodeClient);
+
+    assertThrows(IndexNotFoundException.class, () -> client.getIndexMappings("non_exist_index"));
+  }
+
+  /** Jacoco enforce this constant lambda be tested. */
+  @Test
+  public void testAllFieldsPredicate() {
+    assertTrue(ElasticsearchNodeClient.ALL_FIELDS.apply("any_index").test("any_field"));
+  }
+
+  @Test
+  public void search() {
+    ElasticsearchNodeClient client =
+        new ElasticsearchNodeClient(mock(ClusterService.class), nodeClient);
+
+    // Mock first scroll request
+    SearchResponse searchResponse = mock(SearchResponse.class);
+    when(nodeClient.search(any()).actionGet()).thenReturn(searchResponse);
+    when(searchResponse.getScrollId()).thenReturn("scroll123");
+    when(searchResponse.getHits())
+        .thenReturn(
+            new SearchHits(
+                new SearchHit[] {new SearchHit(1)},
+                new TotalHits(1L, TotalHits.Relation.EQUAL_TO),
+                1.0F));
+
+    // Mock second scroll request followed
+    SearchResponse scrollResponse = mock(SearchResponse.class);
+    when(nodeClient.searchScroll(any()).actionGet()).thenReturn(scrollResponse);
+    when(scrollResponse.getScrollId()).thenReturn("scroll456");
+    when(scrollResponse.getHits()).thenReturn(SearchHits.empty());
+
+    // Verify response for first scroll request
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    ElasticsearchResponse response1 = client.search(request);
+    assertFalse(response1.isEmpty());
+
+    Iterator<SearchHit> hits = response1.iterator();
+    assertTrue(hits.hasNext());
+    assertEquals(new SearchHit(1), hits.next());
+    assertFalse(hits.hasNext());
+
+    // Verify response for second scroll request
+    ElasticsearchResponse response2 = client.search(request);
+    assertTrue(response2.isEmpty());
+  }
+
+  @Test
+  void schedule() {
+    ThreadPool threadPool = mock(ThreadPool.class);
+    when(threadPool.preserveContext(any())).then(invocation -> invocation.getArgument(0));
+    when(nodeClient.threadPool()).thenReturn(threadPool);
+
+    doAnswer(
+        invocation -> {
+          Runnable task = invocation.getArgument(0);
+          task.run();
+          return null;
+        })
+        .when(threadPool)
+        .schedule(any(), any(), any());
+
+    ElasticsearchNodeClient client =
+        new ElasticsearchNodeClient(mock(ClusterService.class), nodeClient);
+    AtomicBoolean isRun = new AtomicBoolean(false);
+    client.schedule(() -> isRun.set(true));
+    assertTrue(isRun.get());
+  }
+
+  @Test
+  void cleanup() {
+    ClearScrollRequestBuilder requestBuilder = mock(ClearScrollRequestBuilder.class);
+    when(nodeClient.prepareClearScroll()).thenReturn(requestBuilder);
+    when(requestBuilder.addScrollId(any())).thenReturn(requestBuilder);
+    when(requestBuilder.get()).thenReturn(null);
+
+    ElasticsearchNodeClient client =
+        new ElasticsearchNodeClient(mock(ClusterService.class), nodeClient);
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    request.setScrollId("scroll123");
+    client.cleanup(request);
+    assertFalse(request.isScrollStarted());
+
+    InOrder inOrder = Mockito.inOrder(nodeClient, requestBuilder);
+    inOrder.verify(nodeClient).prepareClearScroll();
+    inOrder.verify(requestBuilder).addScrollId("scroll123");
+    inOrder.verify(requestBuilder).get();
+  }
+
+  @Test
+  void cleanupWithoutScrollId() {
+    ElasticsearchNodeClient client =
+        new ElasticsearchNodeClient(mock(ClusterService.class), nodeClient);
+
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    client.cleanup(request);
+    verify(nodeClient, never()).prepareClearScroll();
+  }
+
+  private ElasticsearchNodeClient mockClient(String indexName, String mappings) {
+    ClusterService clusterService = mockClusterService(indexName, mappings);
+    return new ElasticsearchNodeClient(clusterService, nodeClient);
+  }
+
+  /** Mock getAliasAndIndexLookup() only for index name resolve test. */
+  public ClusterService mockClusterService(String indexName) {
+    ClusterService mockService = mock(ClusterService.class);
+    ClusterState mockState = mock(ClusterState.class);
+    MetaData mockMetaData = mock(MetaData.class);
+
+    when(mockService.state()).thenReturn(mockState);
+    when(mockState.metaData()).thenReturn(mockMetaData);
+    when(mockMetaData.getAliasAndIndexLookup())
+        .thenReturn(ImmutableSortedMap.of(indexName, mock(AliasOrIndex.class)));
+    return mockService;
+  }
+
+  public ClusterService mockClusterService(String indexName, String mappings) {
+    ClusterService mockService = mock(ClusterService.class);
+    ClusterState mockState = mock(ClusterState.class);
+    MetaData mockMetaData = mock(MetaData.class);
+
+    when(mockService.state()).thenReturn(mockState);
+    when(mockState.metaData()).thenReturn(mockMetaData);
+    try {
+      ImmutableOpenMap.Builder<String, ImmutableOpenMap<String, MappingMetaData>> builder =
+          ImmutableOpenMap.builder();
+      ImmutableOpenMap<String, MappingMetaData> metadata;
+      if (mappings.isEmpty()) {
+        metadata = ImmutableOpenMap.of();
+      } else {
+        metadata = IndexMetaData.fromXContent(createParser(mappings)).getMappings();
+      }
+      builder.put(indexName, metadata);
+      when(mockMetaData.findMappings(any(), any(), any())).thenReturn(builder.build());
+
+      // IndexNameExpressionResolver use this method to check if index exists. If not,
+      // IndexNotFoundException is thrown.
+      when(mockMetaData.getAliasAndIndexLookup())
+          .thenReturn(ImmutableSortedMap.of(indexName, mock(AliasOrIndex.class)));
+    } catch (IOException e) {
+      throw new IllegalStateException("Failed to mock cluster service", e);
     }
-
-    @Test
-    public void getIndexMappingsWithEmptyMapping() {
-        String indexName = "test";
-        ElasticsearchNodeClient client = mockClient(indexName, "");
-        Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
-        assertEquals(1, indexMappings.size());
-
-        IndexMapping indexMapping = indexMappings.values().iterator().next();
-        assertEquals(0, indexMapping.size());
+    return mockService;
+  }
+
+  public ClusterService mockClusterService(String indexName, Throwable t) {
+    ClusterService mockService = mock(ClusterService.class);
+    ClusterState mockState = mock(ClusterState.class);
+    MetaData mockMetaData = mock(MetaData.class);
+
+    when(mockService.state()).thenReturn(mockState);
+    when(mockState.metaData()).thenReturn(mockMetaData);
+    try {
+      when(mockMetaData.findMappings(any(), any(), any())).thenThrow(t);
+      when(mockMetaData.getAliasAndIndexLookup())
+          .thenReturn(ImmutableSortedMap.of(indexName, mock(AliasOrIndex.class)));
+    } catch (IOException e) {
+      throw new IllegalStateException("Failed to mock cluster service", e);
     }
-
-    @Test
-    public void getIndexMappingsWithIOException() {
-        String indexName = "test";
-        ClusterService clusterService = mockClusterService(indexName, new IOException());
-        ElasticsearchNodeClient client = new ElasticsearchNodeClient(clusterService, nodeClient);
-
-        assertThrows(IllegalStateException.class, () -> client.getIndexMappings(indexName));
-    }
-
-    @Test
-    public void getIndexMappingsWithNonExistIndex() {
-        ElasticsearchNodeClient client = new ElasticsearchNodeClient(mockClusterService("test"), nodeClient);
-
-        assertThrows(IndexNotFoundException.class, () -> client.getIndexMappings("non_exist_index"));
-    }
-
-    /** Jacoco enforce this constant lambda be tested */
-    @Test
-    public void testAllFieldsPredicate() {
-        assertTrue(ElasticsearchNodeClient.ALL_FIELDS.apply("any_index").test("any_field"));
-    }
-
-    @Test
-    public void search() {
-        ElasticsearchNodeClient client = new ElasticsearchNodeClient(mock(ClusterService.class),
-                                                                     nodeClient);
-
-        // Mock first scroll request
-        SearchResponse searchResponse = mock(SearchResponse.class);
-        when(nodeClient.search(any()).actionGet()).thenReturn(searchResponse);
-        when(searchResponse.getScrollId()).thenReturn("scroll123");
-        when(searchResponse.getHits()).thenReturn(new SearchHits(new SearchHit[]{new SearchHit(1)},
-                                                                 new TotalHits(1L, TotalHits.Relation.EQUAL_TO),
-                                                                 1.0F));
-
-        // Mock second scroll request followed
-        SearchResponse scrollResponse = mock(SearchResponse.class);
-        when(nodeClient.searchScroll(any()).actionGet()).thenReturn(scrollResponse);
-        when(scrollResponse.getScrollId()).thenReturn("scroll456");
-        when(scrollResponse.getHits()).thenReturn(SearchHits.empty());
-
-        // Verify response for first scroll request
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        ElasticsearchResponse response1 = client.search(request);
-        assertFalse(response1.isEmpty());
-
-        Iterator<SearchHit> hits = response1.iterator();
-        assertTrue(hits.hasNext());
-        assertEquals(new SearchHit(1), hits.next());
-        assertFalse(hits.hasNext());
-
-        // Verify response for second scroll request
-        ElasticsearchResponse response2 = client.search(request);
-        assertTrue(response2.isEmpty());
-    }
-
-    @Test
-    void schedule() {
-        ThreadPool threadPool = mock(ThreadPool.class);
-        when(threadPool.preserveContext(any())).then(invocation -> invocation.getArgument(0));
-        when(nodeClient.threadPool()).thenReturn(threadPool);
-
-        doAnswer(invocation -> {
-            Runnable task = invocation.getArgument(0);
-            task.run();
-            return null;
-        }).when(threadPool).schedule(any(), any(), any());
-
-        ElasticsearchNodeClient client = new ElasticsearchNodeClient(mock(ClusterService.class),
-                                                                     nodeClient);
-        AtomicBoolean isRun = new AtomicBoolean(false);
-        client.schedule(() -> isRun.set(true));
-        assertTrue(isRun.get());
-    }
-
-    @Test
-    void cleanup() {
-        ElasticsearchNodeClient client = new ElasticsearchNodeClient(mock(ClusterService.class),
-                                                                     nodeClient);
-
-        ClearScrollRequestBuilder requestBuilder = mock(ClearScrollRequestBuilder.class);
-        when(nodeClient.prepareClearScroll()).thenReturn(requestBuilder);
-        when(requestBuilder.addScrollId(any())).thenReturn(requestBuilder);
-        when(requestBuilder.get()).thenReturn(null);
-
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        request.setScrollId("scroll123");
-        client.cleanup(request);
-        assertFalse(request.isScrollStarted());
-
-        InOrder inOrder = Mockito.inOrder(nodeClient, requestBuilder);
-        inOrder.verify(nodeClient).prepareClearScroll();
-        inOrder.verify(requestBuilder).addScrollId("scroll123");
-        inOrder.verify(requestBuilder).get();
-    }
-
-    @Test
-    void cleanupWithoutScrollId() {
-        ElasticsearchNodeClient client = new ElasticsearchNodeClient(mock(ClusterService.class),
-                                                                     nodeClient);
-
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        client.cleanup(request);
-        verify(nodeClient, never()).prepareClearScroll();
-    }
-
-    private ElasticsearchNodeClient mockClient(String indexName, String mappings) {
-        ClusterService clusterService = mockClusterService(indexName, mappings);
-        return new ElasticsearchNodeClient(clusterService, nodeClient);
-    }
-
-    /** Mock getAliasAndIndexLookup() only for index name resolve test */
-    public ClusterService mockClusterService(String indexName) {
-        ClusterService mockService = mock(ClusterService.class);
-        ClusterState mockState = mock(ClusterState.class);
-        MetaData mockMetaData = mock(MetaData.class);
-
-        when(mockService.state()).thenReturn(mockState);
-        when(mockState.metaData()).thenReturn(mockMetaData);
-        when(mockMetaData.getAliasAndIndexLookup()).thenReturn(ImmutableSortedMap.of(indexName, mock(AliasOrIndex.class)));
-        return mockService;
-    }
-
-    public ClusterService mockClusterService(String indexName, String mappings) {
-        ClusterService mockService = mock(ClusterService.class);
-        ClusterState mockState = mock(ClusterState.class);
-        MetaData mockMetaData = mock(MetaData.class);
-
-        when(mockService.state()).thenReturn(mockState);
-        when(mockState.metaData()).thenReturn(mockMetaData);
-        try {
-            ImmutableOpenMap.Builder<String, ImmutableOpenMap<String, MappingMetaData>> builder = ImmutableOpenMap.builder();
-            ImmutableOpenMap<String, MappingMetaData> metadata;
-            if (mappings.isEmpty()) {
-                metadata = ImmutableOpenMap.of();
-            } else {
-                metadata = IndexMetaData.fromXContent(createParser(mappings)).getMappings();
-            }
-            builder.put(indexName, metadata);
-            when(mockMetaData.findMappings(any(), any(), any())).thenReturn(builder.build());
-
-            // IndexNameExpressionResolver use this method to check if index exists. If not, IndexNotFoundException is thrown.
-            when(mockMetaData.getAliasAndIndexLookup()).thenReturn(ImmutableSortedMap.of(indexName, mock(AliasOrIndex.class)));
-        }
-        catch (IOException e) {
-            throw new IllegalStateException("Failed to mock cluster service", e);
-        }
-        return mockService;
-    }
-
-    public ClusterService mockClusterService(String indexName, Throwable t) {
-        ClusterService mockService = mock(ClusterService.class);
-        ClusterState mockState = mock(ClusterState.class);
-        MetaData mockMetaData = mock(MetaData.class);
-
-        when(mockService.state()).thenReturn(mockState);
-        when(mockState.metaData()).thenReturn(mockMetaData);
-        try {
-            when(mockMetaData.findMappings(any(), any(), any())).thenThrow(t);
-            when(mockMetaData.getAliasAndIndexLookup()).thenReturn(ImmutableSortedMap.of(indexName, mock(AliasOrIndex.class)));
-        }
-        catch (IOException e) {
-            throw new IllegalStateException("Failed to mock cluster service", e);
-        }
-        return mockService;
-    }
-
-    private XContentParser createParser(String mappings) throws IOException {
-        return XContentType.JSON.xContent().createParser(
-            NamedXContentRegistry.EMPTY,
-            DeprecationHandler.THROW_UNSUPPORTED_OPERATION,
-            mappings
-        );
-    }
-
-}
\ No newline at end of file
+    return mockService;
+  }
+
+  private XContentParser createParser(String mappings) throws IOException {
+    return XContentType.JSON
+        .xContent()
+        .createParser(
+            NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, mappings);
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClientTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClientTest.java
index bd2bf14fb0..95c17a3011 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClientTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/client/ElasticsearchRestClientTest.java
@@ -16,12 +16,28 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.client;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Answers.RETURNS_DEEP_STUBS;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.mapping.IndexMapping;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.request.ElasticsearchRequest;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
 import com.google.common.base.Charsets;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.io.Resources;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.concurrent.atomic.AtomicBoolean;
 import org.apache.lucene.search.TotalHits;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.client.RestHighLevelClient;
@@ -41,161 +57,151 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import java.io.IOException;
-import java.net.URL;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.Answers.RETURNS_DEEP_STUBS;
-import static org.mockito.Mockito.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.never;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchRestClientTest {
 
-    private static final String TEST_MAPPING_FILE = "mappings/accounts.json";
-
-    @Mock(answer = RETURNS_DEEP_STUBS)
-    private RestHighLevelClient restClient;
-
-    private ElasticsearchRestClient client;
-
-    @BeforeEach
-    void setUp() {
-        client = new ElasticsearchRestClient(restClient);
-    }
-
-    @Test
-    void getIndexMappings() throws IOException {
-        URL url = Resources.getResource(TEST_MAPPING_FILE);
-        String mappings = Resources.toString(url, Charsets.UTF_8);
-        String indexName = "test";
-
-        GetMappingsResponse response = mock(GetMappingsResponse.class);
-        when(response.mappings()).thenReturn(mockFieldMappings(indexName, mappings));
-        when(restClient.indices().getMapping(any(GetMappingsRequest.class), any())).thenReturn(response);
-
-        Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
-        assertEquals(1, indexMappings.size());
-
-        IndexMapping indexMapping = indexMappings.values().iterator().next();
-        assertEquals(20, indexMapping.size());
-        assertEquals("text", indexMapping.getFieldType("address"));
-        assertEquals("integer", indexMapping.getFieldType("age"));
-        assertEquals("double", indexMapping.getFieldType("balance"));
-        assertEquals("keyword", indexMapping.getFieldType("city"));
-        assertEquals("date", indexMapping.getFieldType("birthday"));
-        assertEquals("geo_point", indexMapping.getFieldType("location"));
-        assertEquals("some_new_es_type_outside_type_system", indexMapping.getFieldType("new_field"));
-        assertEquals("text", indexMapping.getFieldType("field with spaces"));
-        assertEquals("text", indexMapping.getFieldType("employer"));
-        assertEquals("keyword", indexMapping.getFieldType("employer.raw"));
-        assertEquals("nested", indexMapping.getFieldType("projects"));
-        assertEquals("boolean", indexMapping.getFieldType("projects.active"));
-        assertEquals("date", indexMapping.getFieldType("projects.release"));
-        assertEquals("nested", indexMapping.getFieldType("projects.members"));
-        assertEquals("text", indexMapping.getFieldType("projects.members.name"));
-        assertEquals("object", indexMapping.getFieldType("manager"));
-        assertEquals("text", indexMapping.getFieldType("manager.name"));
-        assertEquals("keyword", indexMapping.getFieldType("manager.name.keyword"));
-        assertEquals("keyword", indexMapping.getFieldType("manager.address"));
-        assertEquals("long", indexMapping.getFieldType("manager.salary"));
-    }
-
-    @Test
-    void getIndexMappingsWithIOException() throws IOException {
-        when(restClient.indices().getMapping(any(GetMappingsRequest.class), any())).thenThrow(new IOException());
-        assertThrows(IllegalStateException.class, () -> client.getIndexMappings("test"));
-    }
-
-    @Test
-    void search() throws IOException {
-        // Mock first scroll request
-        SearchResponse searchResponse = mock(SearchResponse.class);
-        when(restClient.search(any(), any())).thenReturn(searchResponse);
-        when(searchResponse.getScrollId()).thenReturn("scroll123");
-        when(searchResponse.getHits()).thenReturn(new SearchHits(new SearchHit[]{new SearchHit(1)},
-                                                                 new TotalHits(1L, TotalHits.Relation.EQUAL_TO),
-                                                                 1.0F));
-
-        // Mock second scroll request followed
-        SearchResponse scrollResponse = mock(SearchResponse.class);
-        when(restClient.scroll(any(), any())).thenReturn(scrollResponse);
-        when(scrollResponse.getScrollId()).thenReturn("scroll456");
-        when(scrollResponse.getHits()).thenReturn(SearchHits.empty());
-
-        // Verify response for first scroll request
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        ElasticsearchResponse response1 = client.search(request);
-        assertFalse(response1.isEmpty());
-
-        Iterator<SearchHit> hits = response1.iterator();
-        assertTrue(hits.hasNext());
-        assertEquals(new SearchHit(1), hits.next());
-        assertFalse(hits.hasNext());
-
-        // Verify response for second scroll request
-        ElasticsearchResponse response2 = client.search(request);
-        assertTrue(response2.isEmpty());
-    }
-
-    @Test
-    void searchWithIOException() throws IOException {
-        when(restClient.search(any(), any())).thenThrow(new IOException());
-        assertThrows(IllegalStateException.class, () -> client.search(new ElasticsearchRequest("test")));
-    }
-
-    @Test
-    void schedule() {
-        AtomicBoolean isRun = new AtomicBoolean(false);
-        client.schedule(() -> {
-            isRun.set(true);
+  private static final String TEST_MAPPING_FILE = "mappings/accounts.json";
+
+  @Mock(answer = RETURNS_DEEP_STUBS)
+  private RestHighLevelClient restClient;
+
+  private ElasticsearchRestClient client;
+
+  @BeforeEach
+  void setUp() {
+    client = new ElasticsearchRestClient(restClient);
+  }
+
+  @Test
+  void getIndexMappings() throws IOException {
+    URL url = Resources.getResource(TEST_MAPPING_FILE);
+    String mappings = Resources.toString(url, Charsets.UTF_8);
+    String indexName = "test";
+
+    GetMappingsResponse response = mock(GetMappingsResponse.class);
+    when(response.mappings()).thenReturn(mockFieldMappings(indexName, mappings));
+    when(restClient.indices().getMapping(any(GetMappingsRequest.class), any()))
+        .thenReturn(response);
+
+    Map<String, IndexMapping> indexMappings = client.getIndexMappings(indexName);
+    assertEquals(1, indexMappings.size());
+
+    IndexMapping indexMapping = indexMappings.values().iterator().next();
+    assertEquals(20, indexMapping.size());
+    assertEquals("text", indexMapping.getFieldType("address"));
+    assertEquals("integer", indexMapping.getFieldType("age"));
+    assertEquals("double", indexMapping.getFieldType("balance"));
+    assertEquals("keyword", indexMapping.getFieldType("city"));
+    assertEquals("date", indexMapping.getFieldType("birthday"));
+    assertEquals("geo_point", indexMapping.getFieldType("location"));
+    assertEquals("some_new_es_type_outside_type_system", indexMapping.getFieldType("new_field"));
+    assertEquals("text", indexMapping.getFieldType("field with spaces"));
+    assertEquals("text", indexMapping.getFieldType("employer"));
+    assertEquals("keyword", indexMapping.getFieldType("employer.raw"));
+    assertEquals("nested", indexMapping.getFieldType("projects"));
+    assertEquals("boolean", indexMapping.getFieldType("projects.active"));
+    assertEquals("date", indexMapping.getFieldType("projects.release"));
+    assertEquals("nested", indexMapping.getFieldType("projects.members"));
+    assertEquals("text", indexMapping.getFieldType("projects.members.name"));
+    assertEquals("object", indexMapping.getFieldType("manager"));
+    assertEquals("text", indexMapping.getFieldType("manager.name"));
+    assertEquals("keyword", indexMapping.getFieldType("manager.name.keyword"));
+    assertEquals("keyword", indexMapping.getFieldType("manager.address"));
+    assertEquals("long", indexMapping.getFieldType("manager.salary"));
+  }
+
+  @Test
+  void getIndexMappingsWithIOException() throws IOException {
+    when(restClient.indices().getMapping(any(GetMappingsRequest.class), any()))
+        .thenThrow(new IOException());
+    assertThrows(IllegalStateException.class, () -> client.getIndexMappings("test"));
+  }
+
+  @Test
+  void search() throws IOException {
+    // Mock first scroll request
+    SearchResponse searchResponse = mock(SearchResponse.class);
+    when(restClient.search(any(), any())).thenReturn(searchResponse);
+    when(searchResponse.getScrollId()).thenReturn("scroll123");
+    when(searchResponse.getHits())
+        .thenReturn(
+            new SearchHits(
+                new SearchHit[] {new SearchHit(1)},
+                new TotalHits(1L, TotalHits.Relation.EQUAL_TO),
+                1.0F));
+
+    // Mock second scroll request followed
+    SearchResponse scrollResponse = mock(SearchResponse.class);
+    when(restClient.scroll(any(), any())).thenReturn(scrollResponse);
+    when(scrollResponse.getScrollId()).thenReturn("scroll456");
+    when(scrollResponse.getHits()).thenReturn(SearchHits.empty());
+
+    // Verify response for first scroll request
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    ElasticsearchResponse response1 = client.search(request);
+    assertFalse(response1.isEmpty());
+
+    Iterator<SearchHit> hits = response1.iterator();
+    assertTrue(hits.hasNext());
+    assertEquals(new SearchHit(1), hits.next());
+    assertFalse(hits.hasNext());
+
+    // Verify response for second scroll request
+    ElasticsearchResponse response2 = client.search(request);
+    assertTrue(response2.isEmpty());
+  }
+
+  @Test
+  void searchWithIOException() throws IOException {
+    when(restClient.search(any(), any())).thenThrow(new IOException());
+    assertThrows(
+        IllegalStateException.class, () -> client.search(new ElasticsearchRequest("test")));
+  }
+
+  @Test
+  void schedule() {
+    AtomicBoolean isRun = new AtomicBoolean(false);
+    client.schedule(
+        () -> {
+          isRun.set(true);
         });
-        assertTrue(isRun.get());
-    }
-
-    @Test
-    void cleanup() throws IOException {
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        request.setScrollId("scroll123");
-        client.cleanup(request);
-        verify(restClient).clearScroll(any(), any());
-        assertFalse(request.isScrollStarted());
-    }
-
-    @Test
-    void cleanupWithoutScrollId() throws IOException {
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        client.cleanup(request);
-        verify(restClient, never()).clearScroll(any(), any());
-    }
-
-    @Test
-    void cleanupWithIOException() throws IOException {
-        when(restClient.clearScroll(any(), any())).thenThrow(new IOException());
-
-        ElasticsearchRequest request = new ElasticsearchRequest("test");
-        request.setScrollId("scroll123");
-        assertThrows(IllegalStateException.class, () -> client.cleanup(request));
-    }
-
-    private Map<String, MappingMetaData> mockFieldMappings(String indexName, String mappings) throws IOException {
-        return ImmutableMap.of(indexName, IndexMetaData.fromXContent(createParser(mappings)).mapping());
-    }
-
-    private XContentParser createParser(String mappings) throws IOException {
-        return XContentType.JSON.xContent().createParser(
-            NamedXContentRegistry.EMPTY,
-            DeprecationHandler.THROW_UNSUPPORTED_OPERATION,
-            mappings
-        );
-    }
-}
\ No newline at end of file
+    assertTrue(isRun.get());
+  }
+
+  @Test
+  void cleanup() throws IOException {
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    request.setScrollId("scroll123");
+    client.cleanup(request);
+    verify(restClient).clearScroll(any(), any());
+    assertFalse(request.isScrollStarted());
+  }
+
+  @Test
+  void cleanupWithoutScrollId() throws IOException {
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    client.cleanup(request);
+    verify(restClient, never()).clearScroll(any(), any());
+  }
+
+  @Test
+  void cleanupWithIOException() throws IOException {
+    when(restClient.clearScroll(any(), any())).thenThrow(new IOException());
+
+    ElasticsearchRequest request = new ElasticsearchRequest("test");
+    request.setScrollId("scroll123");
+    assertThrows(IllegalStateException.class, () -> client.cleanup(request));
+  }
+
+  private Map<String, MappingMetaData> mockFieldMappings(String indexName, String mappings)
+      throws IOException {
+    return ImmutableMap.of(indexName, IndexMetaData.fromXContent(createParser(mappings)).mapping());
+  }
+
+  private XContentParser createParser(String mappings) throws IOException {
+    return XContentType.JSON
+        .xContent()
+        .createParser(
+            NamedXContentRegistry.EMPTY, DeprecationHandler.THROW_UNSUPPORTED_OPERATION, mappings);
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngineTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngineTest.java
index 6ccd904256..b14b7f0b06 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngineTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/executor/ElasticsearchExecutionEngineTest.java
@@ -16,24 +16,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.executor;
 
-import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
-import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
-import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchClient;
-import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
-import com.amazon.opendistroforelasticsearch.sql.storage.TableScanOperator;
-import lombok.RequiredArgsConstructor;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.extension.ExtendWith;
-import org.mockito.Mock;
-import org.mockito.junit.jupiter.MockitoExtension;
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Iterator;
-import java.util.List;
-import java.util.concurrent.atomic.AtomicReference;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.tupleValue;
 import static com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine.QueryResponse;
 import static com.google.common.collect.ImmutableMap.of;
@@ -46,99 +28,120 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
+import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
+import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
+import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchClient;
+import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
+import com.amazon.opendistroforelasticsearch.sql.storage.TableScanOperator;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+import lombok.RequiredArgsConstructor;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchExecutionEngineTest {
 
-    @Mock
-    private ElasticsearchClient client;
-
-    @BeforeEach
-    void setUp() {
-        doAnswer(invocation -> {
-            // Run task immediately
-            Runnable task = invocation.getArgument(0);
-            task.run();
-            return null;
-        }).when(client).schedule(any());
-    }
-
-    @Test
-    void executeSuccessfully() {
-        List<ExprValue> expected = Arrays.asList(
-            tupleValue(of("name", "John", "age", 20)),
-            tupleValue(of("name", "Allen", "age", 30))
-        );
-        FakePhysicalPlan plan = new FakePhysicalPlan(expected.iterator());
-
-        ElasticsearchExecutionEngine executor = new ElasticsearchExecutionEngine(client);
-        List<ExprValue> actual = new ArrayList<>();
-        executor.execute(plan, new ResponseListener<QueryResponse>() {
-            @Override
-            public void onResponse(QueryResponse response) {
-                actual.addAll(response.getResults());
-            }
-
-            @Override
-            public void onFailure(Exception e) {
-                fail("Error occurred during execution", e);
-            }
+  @Mock private ElasticsearchClient client;
+
+  @BeforeEach
+  void setUp() {
+    doAnswer(
+        invocation -> {
+          // Run task immediately
+          Runnable task = invocation.getArgument(0);
+          task.run();
+          return null;
+        })
+        .when(client)
+        .schedule(any());
+  }
+
+  @Test
+  void executeSuccessfully() {
+    List<ExprValue> expected =
+        Arrays.asList(
+            tupleValue(of("name", "John", "age", 20)), tupleValue(of("name", "Allen", "age", 30)));
+    FakePhysicalPlan plan = new FakePhysicalPlan(expected.iterator());
+
+    ElasticsearchExecutionEngine executor = new ElasticsearchExecutionEngine(client);
+    List<ExprValue> actual = new ArrayList<>();
+    executor.execute(
+        plan,
+        new ResponseListener<QueryResponse>() {
+          @Override
+          public void onResponse(QueryResponse response) {
+            actual.addAll(response.getResults());
+          }
+
+          @Override
+          public void onFailure(Exception e) {
+            fail("Error occurred during execution", e);
+          }
         });
 
-        assertTrue(plan.hasOpen);
-        assertEquals(expected, actual);
-        assertTrue(plan.hasClosed);
+    assertTrue(plan.hasOpen);
+    assertEquals(expected, actual);
+    assertTrue(plan.hasClosed);
+  }
+
+  @Test
+  void executeWithFailure() {
+    PhysicalPlan plan = mock(PhysicalPlan.class);
+    RuntimeException expected = new RuntimeException("Execution error");
+    when(plan.hasNext()).thenThrow(expected);
+
+    ElasticsearchExecutionEngine executor = new ElasticsearchExecutionEngine(client);
+    AtomicReference<Exception> actual = new AtomicReference<>();
+    executor.execute(
+        plan,
+        new ResponseListener<QueryResponse>() {
+          @Override
+          public void onResponse(QueryResponse response) {
+            fail("Expected error didn't happen");
+          }
+
+          @Override
+          public void onFailure(Exception e) {
+            actual.set(e);
+          }
+        });
+    assertEquals(expected, actual.get());
+    verify(plan).close();
+  }
+
+  @RequiredArgsConstructor
+  private static class FakePhysicalPlan extends TableScanOperator {
+    private final Iterator<ExprValue> it;
+    private boolean hasOpen;
+    private boolean hasClosed;
+
+    @Override
+    public void open() {
+      super.open();
+      hasOpen = true;
     }
 
-    @Test
-    void executeWithFailure() {
-        PhysicalPlan plan = mock(PhysicalPlan.class);
-        RuntimeException expected = new RuntimeException("Execution error");
-        when(plan.hasNext()).thenThrow(expected);
-
-        ElasticsearchExecutionEngine executor = new ElasticsearchExecutionEngine(client);
-        AtomicReference<Exception> actual = new AtomicReference<>();
-        executor.execute(plan, new ResponseListener<QueryResponse>() {
-            @Override
-            public void onResponse(QueryResponse response) {
-                fail("Expected error didn't happen");
-            }
-
-            @Override
-            public void onFailure(Exception e) {
-                actual.set(e);
-            }
-        });
-        assertEquals(expected, actual.get());
-        verify(plan).close();
+    @Override
+    public void close() {
+      super.close();
+      hasClosed = true;
     }
 
-    @RequiredArgsConstructor
-    private static class FakePhysicalPlan extends TableScanOperator {
-        private final Iterator<ExprValue> it;
-        private boolean hasOpen;
-        private boolean hasClosed;
-
-        @Override
-        public void open() {
-            super.open();
-            hasOpen = true;
-        }
-
-        @Override
-        public void close() {
-            super.close();
-            hasClosed = true;
-        }
-
-        @Override
-        public boolean hasNext() {
-            return it.hasNext();
-        }
-
-        @Override
-        public ExprValue next() {
-            return it.next();
-        }
+    @Override
+    public boolean hasNext() {
+      return it.hasNext();
     }
 
-}
\ No newline at end of file
+    @Override
+    public ExprValue next() {
+      return it.next();
+    }
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMappingTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMappingTest.java
index 5d82a017db..9dee52341f 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMappingTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/mapping/IndexMappingTest.java
@@ -16,11 +16,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.mapping;
 
-import com.google.common.collect.ImmutableMap;
-import org.junit.jupiter.api.Test;
-
-import java.util.Map;
-
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.aMapWithSize;
 import static org.hamcrest.Matchers.allOf;
@@ -28,27 +23,25 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 
-class IndexMappingTest {
-
-    @Test
-    public void getFieldType() {
-        IndexMapping indexMapping = new IndexMapping(ImmutableMap.of("name", "text"));
-        assertEquals("text", indexMapping.getFieldType("name"));
-        assertNull(indexMapping.getFieldType("not_exist"));
-    }
+import com.google.common.collect.ImmutableMap;
+import java.util.Map;
+import org.junit.jupiter.api.Test;
 
-    @Test
-    public void getAllFieldTypes() {
-        IndexMapping indexMapping = new IndexMapping(ImmutableMap.of("name", "text", "age", "int"));
-        Map<String, String> fieldTypes = indexMapping.getAllFieldTypes(type -> "our_type");
-        assertThat(
-            fieldTypes,
-            allOf(
-                aMapWithSize(2),
-                hasEntry("name", "our_type"),
-                hasEntry("age", "our_type")
-            )
-        );
-    }
+class IndexMappingTest {
 
-}
\ No newline at end of file
+  @Test
+  public void getFieldType() {
+    IndexMapping indexMapping = new IndexMapping(ImmutableMap.of("name", "text"));
+    assertEquals("text", indexMapping.getFieldType("name"));
+    assertNull(indexMapping.getFieldType("not_exist"));
+  }
+
+  @Test
+  public void getAllFieldTypes() {
+    IndexMapping indexMapping = new IndexMapping(ImmutableMap.of("name", "text", "age", "int"));
+    Map<String, String> fieldTypes = indexMapping.getAllFieldTypes(type -> "our_type");
+    assertThat(
+        fieldTypes,
+        allOf(aMapWithSize(2), hasEntry("name", "our_type"), hasEntry("age", "our_type")));
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequestTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequestTest.java
index 44fa83a3f1..cd6600d100 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequestTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/request/ElasticsearchRequestTest.java
@@ -16,49 +16,47 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.request;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.action.search.SearchScrollRequest;
 import org.elasticsearch.index.query.QueryBuilders;
 import org.elasticsearch.search.builder.SearchSourceBuilder;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 class ElasticsearchRequestTest {
 
-    private final ElasticsearchRequest request = new ElasticsearchRequest("test");
-
-    @Test
-    void searchRequest() {
-        request.getSourceBuilder().
-                query(QueryBuilders.termQuery("name", "John"));
-
-        assertEquals(
-            new SearchRequest().indices("test").
-                                scroll(ElasticsearchRequest.DEFAULT_SCROLL_TIMEOUT).
-                                source(new SearchSourceBuilder().query(QueryBuilders.termQuery("name", "John"))),
-            request.searchRequest()
-        );
-    }
-
-    @Test
-    void isScrollStarted() {
-        assertFalse(request.isScrollStarted());
-
-        request.setScrollId("scroll123");
-        assertTrue(request.isScrollStarted());
-    }
-
-    @Test
-    void scrollRequest() {
-        request.setScrollId("scroll123");
-        assertEquals(
-            new SearchScrollRequest().scroll(ElasticsearchRequest.DEFAULT_SCROLL_TIMEOUT).
-                                      scrollId("scroll123"),
-            request.scrollRequest()
-        );
-    }
-
-}
\ No newline at end of file
+  private final ElasticsearchRequest request = new ElasticsearchRequest("test");
+
+  @Test
+  void searchRequest() {
+    request.getSourceBuilder().query(QueryBuilders.termQuery("name", "John"));
+
+    assertEquals(
+        new SearchRequest()
+            .indices("test")
+            .scroll(ElasticsearchRequest.DEFAULT_SCROLL_TIMEOUT)
+            .source(new SearchSourceBuilder().query(QueryBuilders.termQuery("name", "John"))),
+        request.searchRequest());
+  }
+
+  @Test
+  void isScrollStarted() {
+    assertFalse(request.isScrollStarted());
+
+    request.setScrollId("scroll123");
+    assertTrue(request.isScrollStarted());
+  }
+
+  @Test
+  void scrollRequest() {
+    request.setScrollId("scroll123");
+    assertEquals(
+        new SearchScrollRequest()
+            .scroll(ElasticsearchRequest.DEFAULT_SCROLL_TIMEOUT)
+            .scrollId("scroll123"),
+        request.scrollRequest());
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponseTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponseTest.java
index 3a3a52b3e4..68ea1af73d 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponseTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/response/ElasticsearchResponseTest.java
@@ -16,6 +16,12 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.response;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+import static org.mockito.Mockito.when;
+
 import org.apache.lucene.search.TotalHits;
 import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.search.SearchHit;
@@ -26,57 +32,48 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchResponseTest {
 
-    @Mock
-    private SearchResponse esResponse;
+  @Mock private SearchResponse esResponse;
 
-    @BeforeEach
-    void setUp() {
-        when(esResponse.getHits()).thenReturn(
+  @BeforeEach
+  void setUp() {
+    when(esResponse.getHits())
+        .thenReturn(
             new SearchHits(
-                new SearchHit[]{ new SearchHit(1), new SearchHit(2) },
+                new SearchHit[] {new SearchHit(1), new SearchHit(2)},
                 new TotalHits(2L, TotalHits.Relation.EQUAL_TO),
-                1.0F
-            )
-        );
-    }
+                1.0F));
+  }
 
-    @Test
-    void isEmpty() {
-        ElasticsearchResponse response1 = new ElasticsearchResponse(esResponse);
-        assertFalse(response1.isEmpty());
+  @Test
+  void isEmpty() {
+    ElasticsearchResponse response1 = new ElasticsearchResponse(esResponse);
+    assertFalse(response1.isEmpty());
 
-        when(esResponse.getHits()).thenReturn(SearchHits.empty());
-        ElasticsearchResponse response2 = new ElasticsearchResponse(esResponse);
-        assertTrue(response2.isEmpty());
+    when(esResponse.getHits()).thenReturn(SearchHits.empty());
+    ElasticsearchResponse response2 = new ElasticsearchResponse(esResponse);
+    assertTrue(response2.isEmpty());
 
-        when(esResponse.getHits()).thenReturn(
-            new SearchHits(null, new TotalHits(0, TotalHits.Relation.EQUAL_TO), 0));
-        ElasticsearchResponse response3 = new ElasticsearchResponse(esResponse);
-        assertTrue(response3.isEmpty());
-    }
+    when(esResponse.getHits())
+        .thenReturn(new SearchHits(null, new TotalHits(0, TotalHits.Relation.EQUAL_TO), 0));
+    ElasticsearchResponse response3 = new ElasticsearchResponse(esResponse);
+    assertTrue(response3.isEmpty());
+  }
 
-    @Test
-    void iterator() {
-        int i = 0;
-        for (SearchHit hit : new ElasticsearchResponse(esResponse)) {
-            if (i == 0) {
-                assertEquals(new SearchHit(1), hit);
-            } else if (i == 1) {
-                assertEquals(new SearchHit(2), hit);
-            } else {
-                fail("More search hits returned than expected");
-            }
-            i++;
-        }
+  @Test
+  void iterator() {
+    int i = 0;
+    for (SearchHit hit : new ElasticsearchResponse(esResponse)) {
+      if (i == 0) {
+        assertEquals(new SearchHit(1), hit);
+      } else if (i == 1) {
+        assertEquals(new SearchHit(2), hit);
+      } else {
+        fail("More search hits returned than expected");
+      }
+      i++;
     }
-
-}
\ No newline at end of file
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScanTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScanTest.java
index 38768d5050..12e8caebd3 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScanTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexScanTest.java
@@ -16,10 +16,20 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.storage;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchClient;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.response.ElasticsearchResponse;
+import java.util.Arrays;
 import org.elasticsearch.common.bytes.BytesArray;
 import org.elasticsearch.search.SearchHit;
 import org.junit.jupiter.api.Test;
@@ -29,94 +39,78 @@
 import org.mockito.junit.jupiter.MockitoExtension;
 import org.mockito.stubbing.Answer;
 
-import java.util.Arrays;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.junit.jupiter.api.Assertions.fail;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchIndexScanTest {
 
-    @Mock
-    private ElasticsearchClient client;
-
-    @Test
-    void queryEmptyResult() {
-        mockResponse();
-        try (ElasticsearchIndexScan indexScan = new ElasticsearchIndexScan(client, "test")) {
-            indexScan.open();
-            assertFalse(indexScan.hasNext());
-        }
-        verify(client).cleanup(any());
+  @Mock private ElasticsearchClient client;
+
+  @Test
+  void queryEmptyResult() {
+    mockResponse();
+    try (ElasticsearchIndexScan indexScan = new ElasticsearchIndexScan(client, "test")) {
+      indexScan.open();
+      assertFalse(indexScan.hasNext());
     }
+    verify(client).cleanup(any());
+  }
+
+  @Test
+  void queryAllResults() {
+    mockResponse(
+        new SearchHit[] {employee(1, "John", "IT"), employee(2, "Smith", "HR")},
+        new SearchHit[] {employee(3, "Allen", "IT")});
+
+    try (ElasticsearchIndexScan indexScan = new ElasticsearchIndexScan(client, "employees")) {
+      indexScan.open();
+
+      assertTrue(indexScan.hasNext());
+      assertEquals(tupleValue(employee(1, "John", "IT")), indexScan.next());
 
-    @Test
-    void queryAllResults() {
-        mockResponse(
-            new SearchHit[]{
-                employee(1, "John", "IT"),
-                employee(2, "Smith", "HR")
-            },
-            new SearchHit[]{
-                employee(3, "Allen", "IT")
-            }
-        );
-
-        try (ElasticsearchIndexScan indexScan = new ElasticsearchIndexScan(client, "employees")) {
-            indexScan.open();
-
-            assertTrue(indexScan.hasNext());
-            assertEquals(tupleValue(employee(1, "John", "IT")), indexScan.next());
-
-            assertTrue(indexScan.hasNext());
-            assertEquals(tupleValue(employee(2, "Smith", "HR")), indexScan.next());
-
-            assertTrue(indexScan.hasNext());
-            assertEquals(tupleValue(employee(3, "Allen", "IT")), indexScan.next());
-
-            assertFalse(indexScan.hasNext());
-        }
-        verify(client).cleanup(any());
+      assertTrue(indexScan.hasNext());
+      assertEquals(tupleValue(employee(2, "Smith", "HR")), indexScan.next());
+
+      assertTrue(indexScan.hasNext());
+      assertEquals(tupleValue(employee(3, "Allen", "IT")), indexScan.next());
+
+      assertFalse(indexScan.hasNext());
     }
+    verify(client).cleanup(any());
+  }
 
-    private void mockResponse(SearchHit[]... searchHitBatches) {
-        when(client.search(any())).thenAnswer(new Answer<ElasticsearchResponse>() {
-            private int batchNum;
+  private void mockResponse(SearchHit[]... searchHitBatches) {
+    when(client.search(any()))
+        .thenAnswer(
+            new Answer<ElasticsearchResponse>() {
+              private int batchNum;
 
-            @Override
-            public ElasticsearchResponse answer(InvocationOnMock invocation) {
+              @Override
+              public ElasticsearchResponse answer(InvocationOnMock invocation) {
                 ElasticsearchResponse response = mock(ElasticsearchResponse.class);
                 int totalBatch = searchHitBatches.length;
                 if (batchNum < totalBatch) {
-                    when(response.isEmpty()).thenReturn(false);
-                    SearchHit[] searchHit = searchHitBatches[batchNum];
-                    when(response.iterator()).thenReturn(Arrays.asList(searchHit).iterator());
+                  when(response.isEmpty()).thenReturn(false);
+                  SearchHit[] searchHit = searchHitBatches[batchNum];
+                  when(response.iterator()).thenReturn(Arrays.asList(searchHit).iterator());
                 } else if (batchNum == totalBatch) {
-                    when(response.isEmpty()).thenReturn(true);
+                  when(response.isEmpty()).thenReturn(true);
                 } else {
-                    fail("Search request after empty response returned already");
+                  fail("Search request after empty response returned already");
                 }
 
                 batchNum++;
                 return response;
-            }
-        });
-    }
-
-    protected SearchHit employee(int docId, String name, String department) {
-        SearchHit hit = new SearchHit(docId);
-        hit.sourceRef(new BytesArray("{\"name\":\"" + name + "\",\"department\":\"" + department + "\"}"));
-        return hit;
-    }
-
-    private ExprValue tupleValue(SearchHit hit) {
-        return ExprValueUtils.tupleValue(hit.getSourceAsMap());
-    }
-
-}
\ No newline at end of file
+              }
+            });
+  }
+
+  protected SearchHit employee(int docId, String name, String department) {
+    SearchHit hit = new SearchHit(docId);
+    hit.sourceRef(
+        new BytesArray("{\"name\":\"" + name + "\",\"department\":\"" + department + "\"}"));
+    return hit;
+  }
+
+  private ExprValue tupleValue(SearchHit hit) {
+    return ExprValueUtils.tupleValue(hit.getSourceAsMap());
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexTest.java
index 2024e6b0f3..f39d406b18 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchIndexTest.java
@@ -16,6 +16,22 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.storage;
 
+import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.literal;
+import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.ref;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.aggregation;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.eval;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.filter;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.project;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.relation;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.remove;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.rename;
+import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.sort;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.aMapWithSize;
+import static org.hamcrest.Matchers.allOf;
+import static org.hamcrest.Matchers.hasEntry;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
 
 import com.amazon.opendistroforelasticsearch.sql.ast.tree.Sort.SortOption;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprBooleanValue;
@@ -31,6 +47,9 @@
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlanDSL;
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import com.google.common.collect.ImmutableMap;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
 import org.apache.commons.lang3.tuple.ImmutablePair;
 import org.apache.commons.lang3.tuple.Pair;
 import org.junit.jupiter.api.Test;
@@ -38,157 +57,112 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import java.util.Arrays;
-import java.util.List;
-import java.util.Map;
-
-import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.literal;
-import static com.amazon.opendistroforelasticsearch.sql.expression.DSL.ref;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.aggregation;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.dedupe;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.eval;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.filter;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.project;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.relation;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.remove;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.rename;
-import static com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlanDSL.sort;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.aMapWithSize;
-import static org.hamcrest.Matchers.allOf;
-import static org.hamcrest.Matchers.hasEntry;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.mockito.Mockito.when;
-
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchIndexTest {
 
-    @Mock
-    private ElasticsearchClient client;
-
-    @Test
-    void getFieldTypes() {
-        when(client.getIndexMappings("test")).thenReturn(
-            ImmutableMap.of("test", new IndexMapping(
-                ImmutableMap.<String, String>builder().
-                    put("name", "keyword").
-                    put("address", "text").
-                    put("age", "integer").
-                    put("account_number", "long").
-                    put("balance1", "float").
-                    put("balance2", "double").
-                    put("gender", "boolean").
-                    put("family", "nested").
-                    put("employer", "object").
-                    put("birthday", "date").
-                    build()
-                )
-            )
-        );
-
-        Table index = new ElasticsearchIndex(client, "test");
-        Map<String, ExprType> fieldTypes = index.getFieldTypes();
-        assertThat(
-            fieldTypes,
-            allOf(
-                aMapWithSize(10),
-                hasEntry("name", ExprType.STRING),
-                hasEntry("address", ExprType.STRING),
-                hasEntry("age", ExprType.INTEGER),
-                hasEntry("account_number", ExprType.LONG),
-                hasEntry("balance1", ExprType.FLOAT),
-                hasEntry("balance2", ExprType.DOUBLE),
-                hasEntry("gender", ExprType.BOOLEAN),
-                hasEntry("family", ExprType.ARRAY),
-                hasEntry("employer", ExprType.STRUCT),
-                hasEntry("birthday", ExprType.UNKNOWN)
-            )
-        );
-    }
+  @Mock private ElasticsearchClient client;
 
-    @Test
-    void implementRelationOperatorOnly() {
-        String indexName = "test";
-        LogicalPlan plan = relation(indexName);
-        Table index = new ElasticsearchIndex(client, indexName);
-        assertEquals(new ElasticsearchIndexScan(client, indexName), index.implement(plan));
-    }
+  @Test
+  void getFieldTypes() {
+    when(client.getIndexMappings("test"))
+        .thenReturn(
+            ImmutableMap.of(
+                "test",
+                new IndexMapping(
+                    ImmutableMap.<String, String>builder()
+                        .put("name", "keyword")
+                        .put("address", "text")
+                        .put("age", "integer")
+                        .put("account_number", "long")
+                        .put("balance1", "float")
+                        .put("balance2", "double")
+                        .put("gender", "boolean")
+                        .put("family", "nested")
+                        .put("employer", "object")
+                        .put("birthday", "date")
+                        .build())));
 
-    @Test
-    void implementOtherLogicalOperators() {
-        String indexName = "test";
-        ReferenceExpression include = ref("age");
-        ReferenceExpression exclude = ref("name");
-        ReferenceExpression dedupeField = ref("name");
-        Expression filterExpr = literal(ExprBooleanValue.ofTrue());
-        List<Expression> groupByExprs = Arrays.asList(ref("age"));
-        List<Aggregator> aggregators = Arrays.asList(new AvgAggregator(groupByExprs, ExprType.DOUBLE));
-        Map<ReferenceExpression, ReferenceExpression> mappings = ImmutableMap.of(ref("name"), ref("lastname"));
-        Pair<ReferenceExpression, Expression> newEvalField = ImmutablePair.of(ref("name1"), ref("name"));
-        Integer sortCount = 100;
-        Pair<SortOption, Expression> sortField = ImmutablePair.of(SortOption.PPL_ASC, ref("name1"));
+    Table index = new ElasticsearchIndex(client, "test");
+    Map<String, ExprType> fieldTypes = index.getFieldTypes();
+    assertThat(
+        fieldTypes,
+        allOf(
+            aMapWithSize(10),
+            hasEntry("name", ExprType.STRING),
+            hasEntry("address", ExprType.STRING),
+            hasEntry("age", ExprType.INTEGER),
+            hasEntry("account_number", ExprType.LONG),
+            hasEntry("balance1", ExprType.FLOAT),
+            hasEntry("balance2", ExprType.DOUBLE),
+            hasEntry("gender", ExprType.BOOLEAN),
+            hasEntry("family", ExprType.ARRAY),
+            hasEntry("employer", ExprType.STRUCT),
+            hasEntry("birthday", ExprType.UNKNOWN)));
+  }
 
+  @Test
+  void implementRelationOperatorOnly() {
+    String indexName = "test";
+    LogicalPlan plan = relation(indexName);
+    Table index = new ElasticsearchIndex(client, indexName);
+    assertEquals(new ElasticsearchIndexScan(client, indexName), index.implement(plan));
+  }
 
-        LogicalPlan plan =
-            project(
-                LogicalPlanDSL.dedupe(
-                    sort(
-                        eval(
-                            remove(
-                                rename(
-                                    aggregation(
-                                        filter(
-                                            relation(indexName),
-                                            filterExpr
-                                        ),
-                                        aggregators,
-                                        groupByExprs
-                                    ),
-                                    mappings
-                                ),
-                                exclude
-                            ),
-                            newEvalField
-                        ),
-                        sortCount,
-                        sortField
-                    ),
-                    dedupeField
-                ),
-                include
-            );
+  @Test
+  void implementOtherLogicalOperators() {
+    String indexName = "test";
+    ReferenceExpression include = ref("age");
+    ReferenceExpression exclude = ref("name");
+    ReferenceExpression dedupeField = ref("name");
+    Expression filterExpr = literal(ExprBooleanValue.ofTrue());
+    List<Expression> groupByExprs = Arrays.asList(ref("age"));
+    List<Aggregator> aggregators = Arrays.asList(new AvgAggregator(groupByExprs, ExprType.DOUBLE));
+    Map<ReferenceExpression, ReferenceExpression> mappings =
+        ImmutableMap.of(ref("name"), ref("lastname"));
+    Pair<ReferenceExpression, Expression> newEvalField =
+        ImmutablePair.of(ref("name1"), ref("name"));
+    Integer sortCount = 100;
+    Pair<SortOption, Expression> sortField = ImmutablePair.of(SortOption.PPL_ASC, ref("name1"));
 
-        Table index = new ElasticsearchIndex(client, indexName);
-        assertEquals(
-            PhysicalPlanDSL.project(
-                PhysicalPlanDSL.dedupe(
-                    PhysicalPlanDSL.sort(
-                        PhysicalPlanDSL.eval(
-                            PhysicalPlanDSL.remove(
-                                PhysicalPlanDSL.rename(
-                                    PhysicalPlanDSL.agg(
-                                        PhysicalPlanDSL.filter(
-                                            new ElasticsearchIndexScan(client, indexName),
-                                            filterExpr
-                                        ),
-                                        aggregators,
-                                        groupByExprs
-                                    ),
-                                    mappings
-                                ),
-                                exclude
-                            ),
-                            newEvalField
-                        ),
-                        sortCount,
-                        sortField
-                    ),
-                    dedupeField
-                ),
-                include
-            ),
-            index.implement(plan)
-        );
-    }
+    LogicalPlan plan =
+        project(
+            LogicalPlanDSL.dedupe(
+                sort(
+                    eval(
+                        remove(
+                            rename(
+                                aggregation(
+                                    filter(relation(indexName), filterExpr),
+                                    aggregators,
+                                    groupByExprs),
+                                mappings),
+                            exclude),
+                        newEvalField),
+                    sortCount,
+                    sortField),
+                dedupeField),
+            include);
 
-}
\ No newline at end of file
+    Table index = new ElasticsearchIndex(client, indexName);
+    assertEquals(
+        PhysicalPlanDSL.project(
+            PhysicalPlanDSL.dedupe(
+                PhysicalPlanDSL.sort(
+                    PhysicalPlanDSL.eval(
+                        PhysicalPlanDSL.remove(
+                            PhysicalPlanDSL.rename(
+                                PhysicalPlanDSL.agg(
+                                    PhysicalPlanDSL.filter(
+                                        new ElasticsearchIndexScan(client, indexName), filterExpr),
+                                    aggregators,
+                                    groupByExprs),
+                                mappings),
+                            exclude),
+                        newEvalField),
+                    sortCount,
+                    sortField),
+                dedupeField),
+            include),
+        index.implement(plan));
+  }
+}
diff --git a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngineTest.java b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngineTest.java
index 21fdfcc260..f17455f988 100644
--- a/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngineTest.java
+++ b/elasticsearch/src/test/java/com/amazon/opendistroforelasticsearch/sql/elasticsearch/storage/ElasticsearchStorageEngineTest.java
@@ -16,6 +16,8 @@
 
 package com.amazon.opendistroforelasticsearch.sql.elasticsearch.storage;
 
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchClient;
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import org.junit.jupiter.api.Test;
@@ -23,19 +25,15 @@
 import org.mockito.Mock;
 import org.mockito.junit.jupiter.MockitoExtension;
 
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-
 @ExtendWith(MockitoExtension.class)
 class ElasticsearchStorageEngineTest {
 
-    @Mock
-    private ElasticsearchClient client;
-
-    @Test
-    public void getTable() {
-        ElasticsearchStorageEngine engine = new ElasticsearchStorageEngine(client);
-        Table table = engine.getTable("test");
-        assertNotNull(table);
-    }
+  @Mock private ElasticsearchClient client;
 
-}
\ No newline at end of file
+  @Test
+  public void getTable() {
+    ElasticsearchStorageEngine engine = new ElasticsearchStorageEngine(client);
+    Table table = engine.getTable("test");
+    assertNotNull(table);
+  }
+}
diff --git a/integ-test/build.gradle b/integ-test/build.gradle
index c64cbb8cf6..a461d854f8 100644
--- a/integ-test/build.gradle
+++ b/integ-test/build.gradle
@@ -17,11 +17,11 @@ configurations.all {
 }
 
 dependencies {
-    testCompile group: 'org.elasticsearch.test', name: 'framework', version:"${es_version}"
-    testCompile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-high-level-client', version:"${es_version}"
-    testCompile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-client', version:"${es_version}"
+    testCompile group: 'org.elasticsearch.test', name: 'framework', version: "${es_version}"
+    testCompile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-high-level-client', version: "${es_version}"
+    testCompile group: 'org.elasticsearch.client', name: 'elasticsearch-rest-client', version: "${es_version}"
     testCompile group: 'org.hamcrest', name: 'hamcrest', version: '2.1'
-    testCompile group: 'org.apache.logging.log4j', name: 'log4j-core', version:'2.11.1'
+    testCompile group: 'org.apache.logging.log4j', name: 'log4j-core', version: '2.11.1'
     testCompile project(path: ':', configuration: 'integtest')
     testCompile project(':plugin')
     testImplementation('org.junit.jupiter:junit-jupiter-api:5.6.2')
@@ -39,7 +39,7 @@ test {
 
 tasks.integTest.dependsOn(':plugin:bundlePlugin')
 testClusters.integTest {
-    testDistribution='oss'
+    testDistribution = 'oss'
     plugin file(tasks.getByPath(':plugin:bundlePlugin').archiveFile)
 }
 
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/DedupCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/DedupCommandIT.java
index 4518578883..f23ac8d7a0 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/DedupCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/DedupCommandIT.java
@@ -15,48 +15,61 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
-import java.io.IOException;
-import org.json.JSONObject;
-import org.junit.jupiter.api.Test;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_BANK;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_BANK_WITH_NULL_VALUES;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.rows;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyDataRows;
 
+import java.io.IOException;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+
 public class DedupCommandIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.BANK);
-        loadIndex(Index.BANK_WITH_NULL_VALUES);
-    }
-
-    @Test
-    public void testDedup() throws IOException {
-        JSONObject result = executeQuery(String.format("source=%s | dedup male | fields male", TEST_INDEX_BANK));
-        verifyDataRows(result, rows(true), rows(false));
-    }
-
-    @Test
-    public void testConsecutiveDedup() throws IOException {
-        JSONObject result = executeQuery(String.format(
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.BANK);
+    loadIndex(Index.BANK_WITH_NULL_VALUES);
+  }
+
+  @Test
+  public void testDedup() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | dedup male | fields male", TEST_INDEX_BANK));
+    verifyDataRows(result, rows(true), rows(false));
+  }
+
+  @Test
+  public void testConsecutiveDedup() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
                 "source=%s | dedup male consecutive=true | fields male", TEST_INDEX_BANK));
-        verifyDataRows(result, rows(true), rows(false), rows(true), rows(false));
-    }
-
-    @Test
-    public void testAllowMoreDuplicates() throws IOException {
-        JSONObject result = executeQuery(String.format(
-                "source=%s | dedup 2 male | fields male", TEST_INDEX_BANK));
-        verifyDataRows(result, rows(true), rows(true), rows(false), rows(false));
-    }
-
-    @Test
-    public void testKeepEmptyDedup() throws IOException {
-        JSONObject result = executeQuery(String.format(
+    verifyDataRows(result, rows(true), rows(false), rows(true), rows(false));
+  }
+
+  @Test
+  public void testAllowMoreDuplicates() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | dedup 2 male | fields male", TEST_INDEX_BANK));
+    verifyDataRows(result, rows(true), rows(true), rows(false), rows(false));
+  }
+
+  @Test
+  public void testKeepEmptyDedup() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
                 "source=%s | dedup balance keepempty=true | fields firstname, balance",
                 TEST_INDEX_BANK_WITH_NULL_VALUES));
-        verifyDataRows(result, rows("Amber JOHnny", 39225), rows("Hattie"), rows("Nanette", 32838),
-                rows("Dale", 4180), rows("Elinor"), rows("Virginia"), rows("Dillard", 48086));
-    }
+    verifyDataRows(
+        result,
+        rows("Amber JOHnny", 39225),
+        rows("Hattie"),
+        rows("Nanette", 32838),
+        rows("Dale", 4180),
+        rows("Elinor"),
+        rows("Virginia"),
+        rows("Dillard", 48086));
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/FieldsCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/FieldsCommandIT.java
index faa4225520..9d46746a5d 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/FieldsCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/FieldsCommandIT.java
@@ -15,38 +15,42 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
-import java.io.IOException;
-import org.json.JSONObject;
-import org.junit.Ignore;
-import org.junit.jupiter.api.Test;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.columnName;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.columnPattern;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyColumn;
 
+import java.io.IOException;
+import org.json.JSONObject;
+import org.junit.Ignore;
+import org.junit.jupiter.api.Test;
+
 public class FieldsCommandIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.ACCOUNT);
-    }
-
-    @Test
-    public void testFieldsWithOneField() throws IOException {
-        JSONObject result = executeQuery(String.format("source=%s | fields firstname", TEST_INDEX_ACCOUNT));
-        verifyColumn(result, columnName("firstname"));
-    }
-
-    @Test
-    public void testFieldsWithMultiFields() throws IOException {
-        JSONObject result = executeQuery(String.format("source=%s | fields firstname, lastname", TEST_INDEX_ACCOUNT));
-        verifyColumn(result, columnName("firstname"), columnName("lastname"));
-    }
-
-    @Ignore("Cannot resolve wildcard yet")
-    @Test
-    public void testFieldsWildCard() throws IOException {
-        JSONObject result = executeQuery(String.format("source=%s | fields ", TEST_INDEX_ACCOUNT) + "firstnam%");
-        verifyColumn(result, columnPattern("^firstnam.*"));
-    }
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.ACCOUNT);
+  }
+
+  @Test
+  public void testFieldsWithOneField() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | fields firstname", TEST_INDEX_ACCOUNT));
+    verifyColumn(result, columnName("firstname"));
+  }
+
+  @Test
+  public void testFieldsWithMultiFields() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | fields firstname, lastname", TEST_INDEX_ACCOUNT));
+    verifyColumn(result, columnName("firstname"), columnName("lastname"));
+  }
+
+  @Ignore("Cannot resolve wildcard yet")
+  @Test
+  public void testFieldsWildCard() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | fields ", TEST_INDEX_ACCOUNT) + "firstnam%");
+    verifyColumn(result, columnPattern("^firstnam.*"));
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLIntegTestCase.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLIntegTestCase.java
index ac72d51dc2..680d1075bd 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLIntegTestCase.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLIntegTestCase.java
@@ -15,7 +15,12 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestUtils.getResponseBody;
+import static com.amazon.opendistroforelasticsearch.sql.plugin.rest.RestPPLQueryAction.QUERY_API_ENDPOINT;
+
 import com.amazon.opendistroforelasticsearch.sql.esintgtest.RestIntegTestCase;
+import java.io.IOException;
+import java.util.Locale;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.RequestOptions;
 import org.elasticsearch.client.Response;
@@ -23,46 +28,34 @@
 import org.json.JSONObject;
 import org.junit.Assert;
 
-import java.io.IOException;
-import java.util.Locale;
-
-import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestUtils.getResponseBody;
-import static com.amazon.opendistroforelasticsearch.sql.plugin.rest.RestPPLQueryAction.QUERY_API_ENDPOINT;
-
-/**
- * ES Rest integration test base for PPL testing
- */
+/** ES Rest integration test base for PPL testing. */
 public abstract class PPLIntegTestCase extends RestIntegTestCase {
 
-    protected JSONObject executeQuery(String query) throws IOException {
-        return jsonify(executeQueryToString(query));
-    }
-
-    protected String executeQueryToString(String query) throws IOException {
-        Response response = client().performRequest(buildRequest(query));
-        Assert.assertEquals(200, response.getStatusLine().getStatusCode());
-        return getResponseBody(response, true);
-    }
-
-    protected Request buildRequest(String query) {
-        Request request = new Request("POST", QUERY_API_ENDPOINT);
-        request.setJsonEntity(String.format(Locale.ROOT,
-            "{\n" +
-            "  \"query\": \"%s\"\n" +
-            "}", query));
-
-        RequestOptions.Builder restOptionsBuilder = RequestOptions.DEFAULT.toBuilder();
-        restOptionsBuilder.addHeader("Content-Type", "application/json");
-        request.setOptions(restOptionsBuilder);
-        return request;
+  protected JSONObject executeQuery(String query) throws IOException {
+    return jsonify(executeQueryToString(query));
+  }
+
+  protected String executeQueryToString(String query) throws IOException {
+    Response response = client().performRequest(buildRequest(query));
+    Assert.assertEquals(200, response.getStatusLine().getStatusCode());
+    return getResponseBody(response, true);
+  }
+
+  protected Request buildRequest(String query) {
+    Request request = new Request("POST", QUERY_API_ENDPOINT);
+    request.setJsonEntity(String.format(Locale.ROOT, "{\n" + "  \"query\": \"%s\"\n" + "}", query));
+
+    RequestOptions.Builder restOptionsBuilder = RequestOptions.DEFAULT.toBuilder();
+    restOptionsBuilder.addHeader("Content-Type", "application/json");
+    request.setOptions(restOptionsBuilder);
+    return request;
+  }
+
+  private JSONObject jsonify(String text) {
+    try {
+      return new JSONObject(text);
+    } catch (JSONException e) {
+      throw new IllegalStateException(String.format("Failed to transform %s to JSON format", text));
     }
-
-    private JSONObject jsonify(String text) {
-        try {
-            return new JSONObject(text);
-        } catch (JSONException e) {
-            throw new IllegalStateException(String.format("Failed to transform %s to JSON format", text));
-        }
-    }
-
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLPluginIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLPluginIT.java
index c49a9bab52..a6eb31f74b 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLPluginIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLPluginIT.java
@@ -15,6 +15,10 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static org.hamcrest.Matchers.hasProperty;
+
+import java.io.IOException;
+import java.util.Locale;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.Response;
 import org.elasticsearch.client.ResponseException;
@@ -24,69 +28,59 @@
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import java.io.IOException;
-import java.util.Locale;
-
-import static org.hamcrest.Matchers.hasProperty;
-
 public class PPLPluginIT extends PPLIntegTestCase {
-    @Rule
-    public ExpectedException exceptionRule = ExpectedException.none();
+  @Rule public ExpectedException exceptionRule = ExpectedException.none();
 
-    @Override
-    protected void init() throws Exception {
-        wipeAllClusterSettings();
-    }
+  @Override
+  protected void init() throws Exception {
+    wipeAllClusterSettings();
+  }
 
-    @Test
-    public void testQueryEndpointShouldOK() throws IOException {
-        Request request = new Request("PUT", "/a/_doc/1?refresh=true");
-        request.setJsonEntity("{\"name\": \"hello\"}");
-        client().performRequest(request);
+  @Test
+  public void testQueryEndpointShouldOK() throws IOException {
+    Request request = new Request("PUT", "/a/_doc/1?refresh=true");
+    request.setJsonEntity("{\"name\": \"hello\"}");
+    client().performRequest(request);
 
-        String response = executeQueryToString("search source=a");
-        assertEquals(
-            "{\n" +
-            "  \"schema\": [{\n" +
-            "    \"name\": \"name\",\n" +
-            "    \"type\": \"string\"\n" +
-            "  }],\n" +
-            "  \"total\": 1,\n" +
-            "  \"datarows\": [[\"hello\"]],\n" +
-            "  \"size\": 1\n" +
-            "}\n",
-            response
-        );
-    }
+    String response = executeQueryToString("search source=a");
+    assertEquals(
+        "{\n"
+            + "  \"schema\": [{\n"
+            + "    \"name\": \"name\",\n"
+            + "    \"type\": \"string\"\n"
+            + "  }],\n"
+            + "  \"total\": 1,\n"
+            + "  \"datarows\": [[\"hello\"]],\n"
+            + "  \"size\": 1\n"
+            + "}\n",
+        response);
+  }
 
-    @Test
-    public void testQueryEndpointShouldFail() throws IOException {
-        exceptionRule.expect(ResponseException.class);
-        exceptionRule.expect(hasProperty("response", statusCode(500)));
+  @Test
+  public void testQueryEndpointShouldFail() throws IOException {
+    exceptionRule.expect(ResponseException.class);
+    exceptionRule.expect(hasProperty("response", statusCode(500)));
 
-        client().performRequest(makeRequest("search invalid"));
-    }
+    client().performRequest(makeRequest("search invalid"));
+  }
 
-    protected Request makeRequest(String query) {
-        Request post = new Request("POST", "/_opendistro/_ppl");
-        post.setJsonEntity(String.format(Locale.ROOT,
-                "{\n" +
-                        "  \"query\": \"%s\"\n" +
-                        "}", query));
-        return post;
-    }
+  protected Request makeRequest(String query) {
+    Request post = new Request("POST", "/_opendistro/_ppl");
+    post.setJsonEntity(String.format(Locale.ROOT, "{\n" + "  \"query\": \"%s\"\n" + "}", query));
+    return post;
+  }
 
-    private TypeSafeMatcher<Response> statusCode(int statusCode) {
-        return new TypeSafeMatcher<Response>() {
-            @Override
-            public void describeTo(Description description) {
-                description.appendText(String.format(Locale.ROOT, "statusCode=%d", statusCode));
-            }
+  private TypeSafeMatcher<Response> statusCode(int statusCode) {
+    return new TypeSafeMatcher<Response>() {
+      @Override
+      public void describeTo(Description description) {
+        description.appendText(String.format(Locale.ROOT, "statusCode=%d", statusCode));
+      }
 
-            @Override
-            protected boolean matchesSafely(Response resp) {
-                return resp.getStatusLine().getStatusCode() == statusCode;
-            }
-        };
-    }
+      @Override
+      protected boolean matchesSafely(Response resp) {
+        return resp.getStatusLine().getStatusCode() == statusCode;
+      }
+    };
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/QueryAnalysisIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/QueryAnalysisIT.java
index a9de5850e9..534ad5fcf5 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/QueryAnalysisIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/QueryAnalysisIT.java
@@ -15,110 +15,110 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
+
 import com.amazon.opendistroforelasticsearch.sql.exception.SemanticCheckException;
 import java.io.IOException;
 import org.elasticsearch.client.ResponseException;
 import org.junit.Ignore;
 import org.junit.Test;
-import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
 
 public class QueryAnalysisIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.ACCOUNT);
-    }
-
-    /**
-     * Valid commands should pass semantic check
-     */
-    @Test
-    public void searchCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s age=20", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
-    }
-
-    @Test
-    public void whereCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | where age=20", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.ACCOUNT);
+  }
+
+  /** Valid commands should pass semantic check. */
+  @Test
+  public void searchCommandShouldPassSemanticCheck() {
+    String query = String.format("search source=%s age=20", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Test
+  public void whereCommandShouldPassSemanticCheck() {
+    String query = String.format("search source=%s | where age=20", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Test
+  public void fieldsCommandShouldPassSemanticCheck() {
+    String query = String.format("search source=%s | fields firstname", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Ignore("Can't resolve target field yet")
+  @Test
+  public void renameCommandShouldPassSemanticCheck() {
+    String query =
+        String.format("search source=%s | rename firstname as first", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Test
+  public void statsCommandShouldPassSemanticCheck() {
+    String query = String.format("search source=%s | stats avg(age)", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Test
+  public void dedupCommandShouldPassSemanticCheck() {
+    String query =
+        String.format("search source=%s | dedup firstname, lastname", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Test
+  public void sortCommandShouldPassSemanticCheck() {
+    String query = String.format("search source=%s | sort age", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  @Test
+  public void evalCommandShouldPassSemanticCheck() {
+    String query = String.format("search source=%s | eval age=abs(age)", TEST_INDEX_ACCOUNT);
+    queryShouldPassSemanticCheck(query);
+  }
+
+  /**
+   * Commands that fail semantic analysis should throw {@link SemanticCheckException}.
+   */
+  @Test
+  public void unsupportedAggregationShouldFailSemanticCheck() {
+    String query = String.format("search source=%s | stats range(age)", TEST_INDEX_ACCOUNT);
+    queryShouldThrowSemanticException(query, "Unsupported aggregation function range");
+  }
+
+  @Test
+  public void nonexistentFieldShouldFailSemanticCheck() {
+    String query = String.format("search source=%s | fields name", TEST_INDEX_ACCOUNT);
+    queryShouldThrowSemanticException(query, "can't resolve expression name in type env");
+  }
+
+  private void queryShouldPassSemanticCheck(String query) {
+    try {
+      executeQuery(query);
+    } catch (SemanticCheckException e) {
+      fail("Expected to pass semantic check but failed for query: " + query);
+    } catch (IOException e) {
+      throw new IllegalStateException("Unexpected IOException raised for query: " + query);
     }
-
-    @Test
-    public void fieldsCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | fields firstname", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
-    }
-
-    @Ignore("Can't resolve target field yet")
-    @Test
-    public void renameCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | rename firstname as first", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
-    }
-
-    @Test
-    public void statsCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | stats avg(age)", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
-    }
-
-    @Test
-    public void dedupCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | dedup firstname, lastname", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
+  }
+
+  private void queryShouldThrowSemanticException(String query, String... messages) {
+    try {
+      executeQuery(query);
+      fail("Expected to throw SemanticCheckException, but none was thrown for query: " + query);
+    } catch (ResponseException e) {
+      String errorMsg = e.getMessage();
+      assertTrue(errorMsg.contains("SemanticCheckException"));
+      for (String msg : messages) {
+        assertTrue(errorMsg.contains(msg));
+      }
+    } catch (IOException e) {
+      throw new IllegalStateException("Unexpected exception raised for query: " + query);
     }
-
-    @Test
-    public void sortCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | sort age", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
-    }
-
-    @Test
-    public void evalCommandShouldPassSemanticCheck() {
-        String query = String.format("search source=%s | eval age=abs(age)", TEST_INDEX_ACCOUNT);
-        queryShouldPassSemanticCheck(query);
-    }
-
-    /**
-     * Commands that fail semantic analysis should throw {@link SemanticCheckException}
-     */
-    @Test
-    public void unsupportedAggregationShouldFailSemanticCheck() {
-        String query = String.format("search source=%s | stats range(age)", TEST_INDEX_ACCOUNT);
-        queryShouldThrowSemanticException(query, "Unsupported aggregation function range");
-    }
-
-    @Test
-    public void nonexistentFieldShouldFailSemanticCheck() {
-        String query = String.format("search source=%s | fields name", TEST_INDEX_ACCOUNT);
-        queryShouldThrowSemanticException(query, "can't resolve expression name in type env");
-    }
-
-    private void queryShouldPassSemanticCheck(String query) {
-        try {
-            executeQuery(query);
-        } catch (SemanticCheckException e) {
-            fail("Expected to pass semantic check but failed for query: " + query);
-        } catch (IOException e) {
-            throw new IllegalStateException("Unexpected IOException raised for query: " + query);
-        }
-    }
-
-    private void queryShouldThrowSemanticException(String query, String... messages) {
-        try {
-            executeQuery(query);
-            fail("Expected to throw SemanticCheckException, but none was thrown for query: " + query);
-        } catch (ResponseException e) {
-            String errorMsg = e.getMessage();
-            assertTrue(errorMsg.contains("SemanticCheckException"));
-            for (String msg: messages) {
-                assertTrue(errorMsg.contains(msg));
-            }
-        } catch (IOException e) {
-            throw new IllegalStateException("Unexpected exception raised for query: " + query);
-        }
-    }
-
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/RenameCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/RenameCommandIT.java
index 441014d953..95917a03e8 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/RenameCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/RenameCommandIT.java
@@ -15,34 +15,37 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
-import java.io.IOException;
-import org.json.JSONObject;
-import org.junit.Ignore;
-import org.junit.jupiter.api.Test;
-
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.columnName;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.columnPattern;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyColumn;
 
+import java.io.IOException;
+import org.json.JSONObject;
+import org.junit.Ignore;
+import org.junit.jupiter.api.Test;
+
 @Ignore("Rename target cannot be resolved yet")
 public class RenameCommandIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.ACCOUNT);
-    }
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.ACCOUNT);
+  }
 
-    @Test
-    public void testRenameOneField() throws IOException {
-        JSONObject result = executeQuery(String.format(
-                "source=%s | fields firstname | rename firstname as first_name", TEST_INDEX_ACCOUNT));
-        verifyColumn(result, columnName("first_name"));
-    }
+  @Test
+  public void testRenameOneField() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
+                "source=%s | fields firstname | rename firstname as first_name",
+                TEST_INDEX_ACCOUNT));
+    verifyColumn(result, columnName("first_name"));
+  }
 
-    @Test
-    public void testRenameWildcardFields() throws IOException {
-        JSONObject result = executeQuery("source=" + TEST_INDEX_ACCOUNT + " | rename %name as %NAME");
-        verifyColumn(result, columnPattern(".*name$"));
-    }
+  @Test
+  public void testRenameWildcardFields() throws IOException {
+    JSONObject result = executeQuery("source=" + TEST_INDEX_ACCOUNT + " | rename %name as %NAME");
+    verifyColumn(result, columnPattern(".*name$"));
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SearchCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SearchCommandIT.java
index d299143e9c..d294aece0c 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SearchCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SearchCommandIT.java
@@ -15,10 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
-import java.io.IOException;
-import org.elasticsearch.client.ResponseException;
-import org.json.JSONObject;
-import org.junit.jupiter.api.Test;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_BANK;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_DOG;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.columnName;
@@ -26,43 +22,49 @@
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyColumn;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyDataRows;
 
+import java.io.IOException;
+import org.elasticsearch.client.ResponseException;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+
 public class SearchCommandIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.BANK);
-        loadIndex(Index.DOG);
-    }
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.BANK);
+    loadIndex(Index.DOG);
+  }
 
-    @Test
-    public void testSearchAllFields() throws IOException {
-        JSONObject result = executeQuery(String.format("search source=%s", TEST_INDEX_DOG));
-        verifyColumn(result, columnName("dog_name"), columnName("holdersName"), columnName("age"));
-    }
+  @Test
+  public void testSearchAllFields() throws IOException {
+    JSONObject result = executeQuery(String.format("search source=%s", TEST_INDEX_DOG));
+    verifyColumn(result, columnName("dog_name"), columnName("holdersName"), columnName("age"));
+  }
 
-    @Test
-    public void testSearchCommandWithoutSearchKeyword() throws IOException {
-        assertEquals(
-                executeQueryToString(String.format("search source=%s", TEST_INDEX_BANK)),
-                executeQueryToString(String.format("source=%s", TEST_INDEX_BANK))
-        );
-    }
+  @Test
+  public void testSearchCommandWithoutSearchKeyword() throws IOException {
+    assertEquals(
+        executeQueryToString(String.format("search source=%s", TEST_INDEX_BANK)),
+        executeQueryToString(String.format("source=%s", TEST_INDEX_BANK)));
+  }
 
-    @Test
-    public void testSearchCommandWithLogicalExpression() throws IOException {
-        JSONObject result = executeQuery(String.format(
+  @Test
+  public void testSearchCommandWithLogicalExpression() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
                 "search source=%s firstname='Hattie' | fields firstname", TEST_INDEX_BANK));
-        verifyDataRows(result, rows("Hattie"));
-    }
+    verifyDataRows(result, rows("Hattie"));
+  }
 
-    @Test
-    public void searchCommandWithoutSourceShouldFailToParse() throws IOException {
-        try {
-            executeQuery("search firstname='Hattie'");
-            fail();
-        } catch (ResponseException e) {
-            assertTrue(e.getMessage().contains("RuntimeException"));
-            assertTrue(e.getMessage().contains("Failed to parse query due to offending symbol"));
-        }
+  @Test
+  public void searchCommandWithoutSourceShouldFailToParse() throws IOException {
+    try {
+      executeQuery("search firstname='Hattie'");
+      fail();
+    } catch (ResponseException e) {
+      assertTrue(e.getMessage().contains("RuntimeException"));
+      assertTrue(e.getMessage().contains("Failed to parse query due to offending symbol"));
     }
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SortCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SortCommandIT.java
index cea4d038c3..868b122ff2 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SortCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/SortCommandIT.java
@@ -15,53 +15,72 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
-import java.io.IOException;
-import org.json.JSONObject;
-import org.junit.Ignore;
-import org.junit.Test;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_BANK;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_BANK_WITH_NULL_VALUES;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_DOG;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.rows;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyOrder;
 
-public class SortCommandIT extends PPLIntegTestCase {
+import java.io.IOException;
+import org.json.JSONObject;
+import org.junit.Ignore;
+import org.junit.Test;
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.BANK);
-        loadIndex(Index.BANK_WITH_NULL_VALUES);
-        loadIndex(Index.DOG);
-    }
+public class SortCommandIT extends PPLIntegTestCase {
 
-    @Test
-    public void testSortCommand() throws IOException {
-        JSONObject result = executeQuery(String.format("source=%s | sort age | fields age", TEST_INDEX_BANK));
-        verifyOrder(result, rows(28), rows(32), rows(33),
-                rows(34), rows(36), rows(36),rows(39));
-    }
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.BANK);
+    loadIndex(Index.BANK_WITH_NULL_VALUES);
+    loadIndex(Index.DOG);
+  }
 
+  @Test
+  public void testSortCommand() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | sort age | fields age", TEST_INDEX_BANK));
+    verifyOrder(result, rows(28), rows(32), rows(33), rows(34), rows(36), rows(36), rows(39));
+  }
 
-    @Ignore("Order with duplicated value")
-    @Test
-    public void testSortWithNullValue() throws IOException {
-        JSONObject result = executeQuery(String.format(
-                "source=%s | sort balance | fields firstname, balance", TEST_INDEX_BANK_WITH_NULL_VALUES));
-        verifyOrder(result, rows("Hattie"), rows("Elinor"), rows("Virginia"), rows("Dale", 4180),
-                rows("Nanette", 32838), rows("Amber JOHnny", 39225),rows("Dillard", 48086));
-    }
+  @Ignore("Order with duplicated value")
+  @Test
+  public void testSortWithNullValue() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
+                "source=%s | sort balance | fields firstname, balance",
+                TEST_INDEX_BANK_WITH_NULL_VALUES));
+    verifyOrder(
+        result,
+        rows("Hattie"),
+        rows("Elinor"),
+        rows("Virginia"),
+        rows("Dale", 4180),
+        rows("Nanette", 32838),
+        rows("Amber JOHnny", 39225),
+        rows("Dillard", 48086));
+  }
 
-    @Test
-    public void testSortStringField() throws IOException {
-        JSONObject result = executeQuery(String.format("source=%s | sort lastname | fields lastname", TEST_INDEX_BANK));
-        verifyOrder(result, rows("Adams"), rows("Ayala"), rows("Bates"), rows("Bond"),
-                rows("Duke Willmington"), rows("Mcpherson"), rows("Ratliff"));
-    }
+  @Test
+  public void testSortStringField() throws IOException {
+    JSONObject result =
+        executeQuery(String.format("source=%s | sort lastname | fields lastname", TEST_INDEX_BANK));
+    verifyOrder(
+        result,
+        rows("Adams"),
+        rows("Ayala"),
+        rows("Bates"),
+        rows("Bond"),
+        rows("Duke Willmington"),
+        rows("Mcpherson"),
+        rows("Ratliff"));
+  }
 
-    @Test
-    public void testSortMultipleFields() throws IOException {
-        JSONObject result = executeQuery(String.format(
-                "source=%s | sort dog_name, age | fields dog_name, age", TEST_INDEX_DOG));
-        verifyOrder(result, rows("rex", 2), rows("snoopy", 4));
-    }
+  @Test
+  public void testSortMultipleFields() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format("source=%s | sort dog_name, age | fields dog_name, age", TEST_INDEX_DOG));
+    verifyOrder(result, rows("rex", 2), rows("snoopy", 4));
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StandaloneIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StandaloneIT.java
index 6d665fcd48..8907ebb1e6 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StandaloneIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StandaloneIT.java
@@ -16,6 +16,8 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
+
 import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchClient;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.client.ElasticsearchRestClient;
@@ -28,6 +30,8 @@
 import com.amazon.opendistroforelasticsearch.sql.protocol.response.QueryResult;
 import com.amazon.opendistroforelasticsearch.sql.protocol.response.format.SimpleJsonResponseFormatter;
 import com.amazon.opendistroforelasticsearch.sql.storage.StorageEngine;
+import java.io.IOException;
+import java.util.concurrent.atomic.AtomicReference;
 import org.elasticsearch.client.Node;
 import org.elasticsearch.client.Request;
 import org.elasticsearch.client.RestClient;
@@ -36,88 +40,82 @@
 import org.junit.jupiter.api.Test;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
-import java.io.IOException;
-import java.util.concurrent.atomic.AtomicReference;
-
-import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
-
 /**
- * Run PPL with query engine outside Elasticsearch cluster. This IT doesn't require our plugin installed actually.
- * The client application, ex. JDBC driver, needs to initialize all components itself required by ppl service.
+ * Run PPL with query engine outside Elasticsearch cluster. This IT doesn't require our plugin
+ * installed actually. The client application, ex. JDBC driver, needs to initialize all components
+ * itself required by ppl service.
  */
 public class StandaloneIT extends PPLIntegTestCase {
 
-    private RestHighLevelClient restClient;
-
-    private PPLService pplService;
-
-    @Override
-    public void init() {
-        restClient = new RestHighLevelClient(
-            RestClient.builder(client().getNodes().toArray(new Node[0])));
-
-        ElasticsearchClient client = new ElasticsearchRestClient(restClient);
-        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
-        context.registerBean(StorageEngine.class, () -> new ElasticsearchStorageEngine(client));
-        context.registerBean(ExecutionEngine.class, () -> new ElasticsearchExecutionEngine(client));
-        context.register(PPLServiceConfig.class);
-        context.refresh();
-
-        pplService = context.getBean(PPLService.class);
-    }
-
-    @AfterEach
-    public void tearDown() throws Exception {
-        restClient.close();
-        super.tearDown();
-    }
-
-    @Test
-    public void testSourceFieldQuery() throws IOException {
-        Request request1 = new Request("PUT", "/test/_doc/1?refresh=true");
-        request1.setJsonEntity("{\"name\": \"hello\", \"age\": 20}");
-        client().performRequest(request1);
-        Request request2 = new Request("PUT", "/test/_doc/2?refresh=true");
-        request2.setJsonEntity("{\"name\": \"world\", \"age\": 30}");
-        client().performRequest(request2);
-
-        String actual = executeByStandaloneQueryEngine("source=test | fields name");
-        assertEquals(
-            "{\n" +
-            "  \"schema\": [{\n" +
-            "    \"name\": \"name\",\n" +
-            "    \"type\": \"string\"\n" +
-            "  }],\n" +
-            "  \"total\": 2,\n" +
-            "  \"datarows\": [\n" +
-            "    [\"hello\"],\n" +
-            "    [\"world\"]\n" +
-            "  ],\n" +
-            "  \"size\": 2\n" +
-            "}",
-            actual
-        );
-    }
-
-    private String executeByStandaloneQueryEngine(String query) {
-        AtomicReference<String> actual = new AtomicReference<>();
-        pplService.execute(
-            new PPLQueryRequest(query, null),
-            new ResponseListener<QueryResponse>() {
-
-                @Override
-                public void onResponse(QueryResponse response) {
-                    QueryResult result = new QueryResult(response.getResults());
-                    String json = new SimpleJsonResponseFormatter(PRETTY).format(result);
-                    actual.set(json);
-                }
-
-                @Override
-                public void onFailure(Exception e) {
-                    throw new IllegalStateException("Exception happened during execution", e);
-                }
-            });
-        return actual.get();
-    }
-
+  private RestHighLevelClient restClient;
+
+  private PPLService pplService;
+
+  @Override
+  public void init() {
+    restClient =
+        new RestHighLevelClient(RestClient.builder(client().getNodes().toArray(new Node[0])));
+
+    ElasticsearchClient client = new ElasticsearchRestClient(restClient);
+    AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+    context.registerBean(StorageEngine.class, () -> new ElasticsearchStorageEngine(client));
+    context.registerBean(ExecutionEngine.class, () -> new ElasticsearchExecutionEngine(client));
+    context.register(PPLServiceConfig.class);
+    context.refresh();
+
+    pplService = context.getBean(PPLService.class);
+  }
+
+  @AfterEach
+  public void tearDown() throws Exception {
+    restClient.close();
+    super.tearDown();
+  }
+
+  @Test
+  public void testSourceFieldQuery() throws IOException {
+    Request request1 = new Request("PUT", "/test/_doc/1?refresh=true");
+    request1.setJsonEntity("{\"name\": \"hello\", \"age\": 20}");
+    client().performRequest(request1);
+    Request request2 = new Request("PUT", "/test/_doc/2?refresh=true");
+    request2.setJsonEntity("{\"name\": \"world\", \"age\": 30}");
+    client().performRequest(request2);
+
+    String actual = executeByStandaloneQueryEngine("source=test | fields name");
+    assertEquals(
+        "{\n"
+            + "  \"schema\": [{\n"
+            + "    \"name\": \"name\",\n"
+            + "    \"type\": \"string\"\n"
+            + "  }],\n"
+            + "  \"total\": 2,\n"
+            + "  \"datarows\": [\n"
+            + "    [\"hello\"],\n"
+            + "    [\"world\"]\n"
+            + "  ],\n"
+            + "  \"size\": 2\n"
+            + "}",
+        actual);
+  }
+
+  private String executeByStandaloneQueryEngine(String query) {
+    AtomicReference<String> actual = new AtomicReference<>();
+    pplService.execute(
+        new PPLQueryRequest(query, null),
+        new ResponseListener<QueryResponse>() {
+
+          @Override
+          public void onResponse(QueryResponse response) {
+            QueryResult result = new QueryResult(response.getResults());
+            String json = new SimpleJsonResponseFormatter(PRETTY).format(result);
+            actual.set(json);
+          }
+
+          @Override
+          public void onFailure(Exception e) {
+            throw new IllegalStateException("Exception happened during execution", e);
+          }
+        });
+    return actual.get();
+  }
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StatsCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StatsCommandIT.java
index 2b5c1f4c87..6dd1d399ee 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StatsCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/StatsCommandIT.java
@@ -15,21 +15,23 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
+
 import java.io.IOException;
 import org.junit.jupiter.api.Test;
-import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
 
 public class StatsCommandIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.ACCOUNT);
-    }
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.ACCOUNT);
+  }
 
-    @Test
-    public void testStatsAvg() throws IOException {
-        String result = executeQueryToString(String.format("source=%s | stats avg(age)", TEST_INDEX_ACCOUNT));
-        assertEquals(
+  @Test
+  public void testStatsAvg() throws IOException {
+    String result =
+        executeQueryToString(String.format("source=%s | stats avg(age)", TEST_INDEX_ACCOUNT));
+    assertEquals(
         "{\n"
             + "  \"schema\": [{\n"
             + "    \"name\": \"avg(age)\",\n"
@@ -39,13 +41,14 @@ public void testStatsAvg() throws IOException {
             + "  \"datarows\": [[30.171]],\n"
             + "  \"size\": 1\n"
             + "}\n",
-                result);
-    }
+        result);
+  }
 
-    @Test
-    public void testStatsSum() throws IOException {
-        String result = executeQueryToString(String.format("source=%s | stats sum(balance)", TEST_INDEX_ACCOUNT));
-        assertEquals(
+  @Test
+  public void testStatsSum() throws IOException {
+    String result =
+        executeQueryToString(String.format("source=%s | stats sum(balance)", TEST_INDEX_ACCOUNT));
+    assertEquals(
         "{\n"
             + "  \"schema\": [{\n"
             + "    \"name\": \"sum(balance)\",\n"
@@ -55,13 +58,15 @@ public void testStatsSum() throws IOException {
             + "  \"datarows\": [[25714837]],\n"
             + "  \"size\": 1\n"
             + "}\n",
-                result);
-    }
+        result);
+  }
 
-    @Test
-    public void testStatsCount() throws IOException {
-        String result = executeQueryToString(String.format("source=%s | stats count(account_number)", TEST_INDEX_ACCOUNT));
-        assertEquals(
+  @Test
+  public void testStatsCount() throws IOException {
+    String result =
+        executeQueryToString(
+            String.format("source=%s | stats count(account_number)", TEST_INDEX_ACCOUNT));
+    assertEquals(
         "{\n"
             + "  \"schema\": [{\n"
             + "    \"name\": \"count(account_number)\",\n"
@@ -71,8 +76,8 @@ public void testStatsCount() throws IOException {
             + "  \"datarows\": [[1000]],\n"
             + "  \"size\": 1\n"
             + "}\n",
-                result);
-    }
+        result);
+  }
 
-    //TODO: each stats aggregate function should be tested here when implemented
+  // TODO: each stats aggregate function should be tested here when implemented
 }
diff --git a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/WhereCommandIT.java b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/WhereCommandIT.java
index af87eaaa18..17e5d3c1c3 100644
--- a/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/WhereCommandIT.java
+++ b/integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/WhereCommandIT.java
@@ -15,40 +15,48 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
-import java.io.IOException;
-import org.json.JSONObject;
-import org.junit.jupiter.api.Test;
 import static com.amazon.opendistroforelasticsearch.sql.esintgtest.TestsConstants.TEST_INDEX_ACCOUNT;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.rows;
 import static com.amazon.opendistroforelasticsearch.sql.util.MatcherUtils.verifyDataRows;
 
+import java.io.IOException;
+import org.json.JSONObject;
+import org.junit.jupiter.api.Test;
+
 public class WhereCommandIT extends PPLIntegTestCase {
 
-    @Override
-    public void init() throws IOException {
-        loadIndex(Index.ACCOUNT);
-    }
-
-    @Test
-    public void testWhereWithLogicalExpr() throws IOException {
-        JSONObject result = executeQuery(String.format(
-                "source=%s | fields firstname | where firstname='Amber' | fields firstname", TEST_INDEX_ACCOUNT));
-        verifyDataRows(result, rows("Amber"));
-    }
-
-    @Test
-    public void testWhereWithMultiLogicalExpr() throws IOException {
-        JSONObject result = executeQuery(String.format(
-                "source=%s | where firstname='Amber' lastname='Duke' age=32 | fields firstname, lastname, age",
+  @Override
+  public void init() throws IOException {
+    loadIndex(Index.ACCOUNT);
+  }
+
+  @Test
+  public void testWhereWithLogicalExpr() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
+                "source=%s | fields firstname | where firstname='Amber' | fields firstname",
                 TEST_INDEX_ACCOUNT));
-        verifyDataRows(result, rows("Amber", "Duke", 32));
-    }
-
-    @Test
-    public void testWhereEquivalentSortCommand() throws IOException {
-        assertEquals(
-                executeQueryToString(String.format("source=%s | where firstname='Amber'", TEST_INDEX_ACCOUNT)),
-                executeQueryToString(String.format("source=%s firstname='Amber'", TEST_INDEX_ACCOUNT))
-        );
-    }
+    verifyDataRows(result, rows("Amber"));
+  }
+
+  @Test
+  public void testWhereWithMultiLogicalExpr() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
+                "source=%s "
+                    + "| where firstname='Amber' lastname='Duke' age=32 "
+                    + "| fields firstname, lastname, age",
+                TEST_INDEX_ACCOUNT));
+    verifyDataRows(result, rows("Amber", "Duke", 32));
+  }
+
+  @Test
+  public void testWhereEquivalentSortCommand() throws IOException {
+    assertEquals(
+        executeQueryToString(
+            String.format("source=%s | where firstname='Amber'", TEST_INDEX_ACCOUNT)),
+        executeQueryToString(String.format("source=%s firstname='Amber'", TEST_INDEX_ACCOUNT)));
+  }
 }
diff --git a/plugin/build.gradle b/plugin/build.gradle
index f8f7288cb0..0f48ae0038 100644
--- a/plugin/build.gradle
+++ b/plugin/build.gradle
@@ -1,6 +1,8 @@
-apply plugin: 'java'
-apply plugin: 'idea'
-apply plugin: 'elasticsearch.esplugin'
+plugins {
+    id 'java'
+    id 'jacoco'
+    id 'elasticsearch.esplugin'
+}
 
 ext {
     projectSubstitutions = [:]
diff --git a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/SQLPlugin.java b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/SQLPlugin.java
index 0fec7c03dc..7e276a9e78 100644
--- a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/SQLPlugin.java
+++ b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/SQLPlugin.java
@@ -16,6 +16,11 @@
 package com.amazon.opendistroforelasticsearch.sql.plugin;
 
 import com.amazon.opendistroforelasticsearch.sql.plugin.rest.RestPPLQueryAction;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+import java.util.function.Supplier;
 import org.elasticsearch.client.Client;
 import org.elasticsearch.cluster.metadata.IndexNameExpressionResolver;
 import org.elasticsearch.cluster.node.DiscoveryNodes;
@@ -36,38 +41,38 @@
 import org.elasticsearch.threadpool.ThreadPool;
 import org.elasticsearch.watcher.ResourceWatcherService;
 
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.List;
-import java.util.Objects;
-import java.util.function.Supplier;
-
 public class SQLPlugin extends Plugin implements ActionPlugin {
 
-    private ClusterService clusterService;
+  private ClusterService clusterService;
 
-    @Override
-    public List<RestHandler> getRestHandlers(Settings settings, RestController restController,
-                                             ClusterSettings clusterSettings, IndexScopedSettings indexScopedSettings,
-                                             SettingsFilter settingsFilter,
-                                             IndexNameExpressionResolver indexNameExpressionResolver,
-                                             Supplier<DiscoveryNodes> nodesInCluster) {
-        Objects.requireNonNull(clusterService, "Cluster service is required");
-        return Arrays.asList(
-                new RestPPLQueryAction(restController, clusterService)
-        );
-    }
+  @Override
+  public List<RestHandler> getRestHandlers(Settings settings, RestController restController,
+                                           ClusterSettings clusterSettings,
+                                           IndexScopedSettings indexScopedSettings,
+                                           SettingsFilter settingsFilter,
+                                           IndexNameExpressionResolver indexNameExpressionResolver,
+                                           Supplier<DiscoveryNodes> nodesInCluster) {
+    Objects.requireNonNull(clusterService, "Cluster service is required");
+    return Arrays.asList(
+        new RestPPLQueryAction(restController, clusterService)
+    );
+  }
 
-    @Override
-    public Collection<Object> createComponents(Client client, ClusterService clusterService, ThreadPool threadPool,
-                                               ResourceWatcherService resourceWatcherService, ScriptService scriptService,
-                                               NamedXContentRegistry xContentRegistry, Environment environment,
-                                               NodeEnvironment nodeEnvironment, NamedWriteableRegistry namedWriteableRegistry,
-                                               IndexNameExpressionResolver indexNameExpressionResolver) {
-        this.clusterService = clusterService;
-        return super.createComponents(client, clusterService, threadPool, resourceWatcherService, scriptService,
-                                      xContentRegistry, environment, nodeEnvironment, namedWriteableRegistry,
-                                      indexNameExpressionResolver);
-    }
+  @Override
+  public Collection<Object> createComponents(Client client, ClusterService clusterService,
+                                             ThreadPool threadPool,
+                                             ResourceWatcherService resourceWatcherService,
+                                             ScriptService scriptService,
+                                             NamedXContentRegistry contentRegistry,
+                                             Environment environment,
+                                             NodeEnvironment nodeEnvironment,
+                                             NamedWriteableRegistry namedWriteableRegistry,
+                                             IndexNameExpressionResolver resolver) {
+    this.clusterService = clusterService;
+    return super
+        .createComponents(client, clusterService, threadPool, resourceWatcherService, scriptService,
+            contentRegistry, environment, nodeEnvironment, namedWriteableRegistry,
+            resolver);
+  }
 
 }
diff --git a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/request/PPLQueryRequestFactory.java b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/request/PPLQueryRequestFactory.java
index f29653b5a5..99eb56e457 100644
--- a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/request/PPLQueryRequestFactory.java
+++ b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/request/PPLQueryRequestFactory.java
@@ -20,39 +20,48 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
+/**
+ * Factory of {@link PPLQueryRequest}.
+ */
 public class PPLQueryRequestFactory {
-    private static final String PPL_URL_PARAM_KEY = "ppl";
-    private static final String PPL_FIELD_NAME = "query";
+  private static final String PPL_URL_PARAM_KEY = "ppl";
+  private static final String PPL_FIELD_NAME = "query";
 
-    public static PPLQueryRequest getPPLRequest(RestRequest request) {
-        switch (request.method()) {
-            case GET:
-                return parsePPLRequestFromUrl(request);
-            case POST:
-                return parsePPLRequestFromPayload(request);
-            default:
-                throw new IllegalArgumentException("ES PPL doesn't supported HTTP " + request.method().name());
-        }
+  /**
+   * Build {@link PPLQueryRequest} from {@link RestRequest}.
+   * @param request {@link PPLQueryRequest}
+   * @return {@link RestRequest}
+   */
+  public static PPLQueryRequest getPPLRequest(RestRequest request) {
+    switch (request.method()) {
+      case GET:
+        return parsePPLRequestFromUrl(request);
+      case POST:
+        return parsePPLRequestFromPayload(request);
+      default:
+        throw new IllegalArgumentException(
+            "ES PPL doesn't supported HTTP " + request.method().name());
     }
+  }
 
-    private static PPLQueryRequest parsePPLRequestFromUrl(RestRequest restRequest) {
-        String ppl;
+  private static PPLQueryRequest parsePPLRequestFromUrl(RestRequest restRequest) {
+    String ppl;
 
-        ppl = restRequest.param(PPL_URL_PARAM_KEY);
-        if (ppl == null) {
-            throw new IllegalArgumentException("Cannot find ppl parameter from the URL");
-        }
-        return new PPLQueryRequest(ppl, null);
+    ppl = restRequest.param(PPL_URL_PARAM_KEY);
+    if (ppl == null) {
+      throw new IllegalArgumentException("Cannot find ppl parameter from the URL");
     }
+    return new PPLQueryRequest(ppl, null);
+  }
 
-    private static PPLQueryRequest parsePPLRequestFromPayload(RestRequest restRequest) {
-        String content = restRequest.content().utf8ToString();
-        JSONObject jsonContent;
-        try {
-            jsonContent = new JSONObject(content);
-        } catch (JSONException e) {
-            throw new IllegalArgumentException("Failed to parse request payload", e);
-        }
-        return new PPLQueryRequest(jsonContent.getString(PPL_FIELD_NAME), jsonContent);
+  private static PPLQueryRequest parsePPLRequestFromPayload(RestRequest restRequest) {
+    String content = restRequest.content().utf8ToString();
+    JSONObject jsonContent;
+    try {
+      jsonContent = new JSONObject(content);
+    } catch (JSONException e) {
+      throw new IllegalArgumentException("Failed to parse request payload", e);
     }
+    return new PPLQueryRequest(jsonContent.getString(PPL_FIELD_NAME), jsonContent);
+  }
 }
diff --git a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/ElasticsearchPluginConfig.java b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/ElasticsearchPluginConfig.java
index 881a88f12e..1fc60b6bbd 100644
--- a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/ElasticsearchPluginConfig.java
+++ b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/ElasticsearchPluginConfig.java
@@ -35,25 +35,25 @@
 @Configuration
 public class ElasticsearchPluginConfig {
 
-    @Autowired
-    private ClusterService clusterService;
-
-    @Autowired
-    private NodeClient nodeClient;
-
-    @Bean
-    public ElasticsearchClient client() {
-        return new ElasticsearchNodeClient(clusterService, nodeClient);
-    }
-
-    @Bean
-    public StorageEngine storageEngine() {
-        return new ElasticsearchStorageEngine(client());
-    }
-
-    @Bean
-    public ExecutionEngine executionEngine() {
-        return new ElasticsearchExecutionEngine(client());
-    }
+  @Autowired
+  private ClusterService clusterService;
+
+  @Autowired
+  private NodeClient nodeClient;
+
+  @Bean
+  public ElasticsearchClient client() {
+    return new ElasticsearchNodeClient(clusterService, nodeClient);
+  }
+
+  @Bean
+  public StorageEngine storageEngine() {
+    return new ElasticsearchStorageEngine(client());
+  }
+
+  @Bean
+  public ExecutionEngine executionEngine() {
+    return new ElasticsearchExecutionEngine(client());
+  }
 
 }
diff --git a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/RestPPLQueryAction.java b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/RestPPLQueryAction.java
index 18aa1cd742..6785f91237 100644
--- a/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/RestPPLQueryAction.java
+++ b/plugin/src/main/java/com/amazon/opendistroforelasticsearch/sql/plugin/rest/RestPPLQueryAction.java
@@ -15,6 +15,10 @@
 
 package com.amazon.opendistroforelasticsearch.sql.plugin.rest;
 
+import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
+import static org.elasticsearch.rest.RestStatus.INTERNAL_SERVER_ERROR;
+import static org.elasticsearch.rest.RestStatus.OK;
+
 import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
 import com.amazon.opendistroforelasticsearch.sql.elasticsearch.security.SecurityAccess;
 import com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine.QueryResponse;
@@ -23,6 +27,10 @@
 import com.amazon.opendistroforelasticsearch.sql.ppl.config.PPLServiceConfig;
 import com.amazon.opendistroforelasticsearch.sql.protocol.response.QueryResult;
 import com.amazon.opendistroforelasticsearch.sql.protocol.response.format.SimpleJsonResponseFormatter;
+import java.io.IOException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Collections;
+import java.util.List;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.elasticsearch.client.node.NodeClient;
@@ -35,87 +43,80 @@
 import org.elasticsearch.rest.RestStatus;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
-import java.io.IOException;
-import java.security.PrivilegedExceptionAction;
-import java.util.Collections;
-import java.util.List;
-
-import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
-import static org.elasticsearch.rest.RestStatus.INTERNAL_SERVER_ERROR;
-import static org.elasticsearch.rest.RestStatus.OK;
-
 public class RestPPLQueryAction extends BaseRestHandler {
-    public static final String QUERY_API_ENDPOINT = "/_opendistro/_ppl";
-
-    private static final Logger LOG = LogManager.getLogger();
-
-    /**
-     * Cluster service required by bean initialization
-     */
-    private final ClusterService clusterService;
-
-    public RestPPLQueryAction(RestController restController, ClusterService clusterService) {
-        super();
-        this.clusterService = clusterService;
-    }
-
-    @Override
-    public List<Route> routes() {
-        return Collections.singletonList(
-            new Route(RestRequest.Method.POST, QUERY_API_ENDPOINT)
-        );
-    }
-
-    @Override
-    public String getName() {
-        return "ppl_query_action";
-    }
-
-    @Override
-    protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient nodeClient) {
-        PPLService pplService = createPPLService(nodeClient);
-        return channel -> pplService.execute(
-            PPLQueryRequestFactory.getPPLRequest(request), createListener(channel));
-    }
-
-    private PPLService createPPLService(NodeClient client) {
-        return doPrivileged(() -> {
-            AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
-            context.registerBean(ClusterService.class, () -> clusterService);
-            context.registerBean(NodeClient.class, () -> client);
-            context.register(ElasticsearchPluginConfig.class);
-            context.register(PPLServiceConfig.class);
-            context.refresh();
-            return context.getBean(PPLService.class);
-        });
-    }
-
-    private ResponseListener<QueryResponse> createListener(RestChannel channel) {
-        SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(PRETTY); // TODO: decide format and pretty from URL param
-        return new ResponseListener<QueryResponse>() {
-            @Override
-            public void onResponse(QueryResponse response) {
-                sendResponse(OK, formatter.format(new QueryResult(response.getResults())));
-            }
-
-            @Override
-            public void onFailure(Exception e) {
-                LOG.error("Error happened during query handling", e);
-                sendResponse(INTERNAL_SERVER_ERROR, formatter.format(e));
-            }
-
-            private void sendResponse(RestStatus status, String content) {
-                channel.sendResponse(new BytesRestResponse(status, "application/json; charset=UTF-8", content));
-            }
-        };
-    }
-
-    private <T> T doPrivileged(PrivilegedExceptionAction<T> action) {
-        try {
-            return SecurityAccess.doPrivileged(action);
-        } catch (IOException e) {
-            throw new IllegalStateException("Failed to perform privileged action", e);
-        }
+  public static final String QUERY_API_ENDPOINT = "/_opendistro/_ppl";
+
+  private static final Logger LOG = LogManager.getLogger();
+
+  /**
+   * Cluster service required by bean initialization.
+   */
+  private final ClusterService clusterService;
+
+  public RestPPLQueryAction(RestController restController, ClusterService clusterService) {
+    super();
+    this.clusterService = clusterService;
+  }
+
+  @Override
+  public List<Route> routes() {
+    return Collections.singletonList(
+        new Route(RestRequest.Method.POST, QUERY_API_ENDPOINT)
+    );
+  }
+
+  @Override
+  public String getName() {
+    return "ppl_query_action";
+  }
+
+  @Override
+  protected RestChannelConsumer prepareRequest(RestRequest request, NodeClient nodeClient) {
+    PPLService pplService = createPPLService(nodeClient);
+    return channel -> pplService.execute(
+        PPLQueryRequestFactory.getPPLRequest(request), createListener(channel));
+  }
+
+  private PPLService createPPLService(NodeClient client) {
+    return doPrivileged(() -> {
+      AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+      context.registerBean(ClusterService.class, () -> clusterService);
+      context.registerBean(NodeClient.class, () -> client);
+      context.register(ElasticsearchPluginConfig.class);
+      context.register(PPLServiceConfig.class);
+      context.refresh();
+      return context.getBean(PPLService.class);
+    });
+  }
+
+  private ResponseListener<QueryResponse> createListener(RestChannel channel) {
+    SimpleJsonResponseFormatter formatter =
+        new SimpleJsonResponseFormatter(PRETTY); // TODO: decide format and pretty from URL param
+    return new ResponseListener<QueryResponse>() {
+      @Override
+      public void onResponse(QueryResponse response) {
+        sendResponse(OK, formatter.format(new QueryResult(response.getResults())));
+      }
+
+      @Override
+      public void onFailure(Exception e) {
+        LOG.error("Error happened during query handling", e);
+        sendResponse(INTERNAL_SERVER_ERROR, formatter.format(e));
+      }
+
+      private void sendResponse(RestStatus status, String content) {
+        channel.sendResponse(
+            new BytesRestResponse(status, "application/json; charset=UTF-8", content));
+      }
+    };
+  }
+
+  private <T> T doPrivileged(PrivilegedExceptionAction<T> action) {
+    try {
+      return SecurityAccess.doPrivileged(action);
+    } catch (IOException e) {
+      throw new IllegalStateException("Failed to perform privileged action", e);
     }
+  }
 
 }
diff --git a/ppl/build.gradle b/ppl/build.gradle
index b3869a4fde..3818d805f4 100644
--- a/ppl/build.gradle
+++ b/ppl/build.gradle
@@ -25,9 +25,9 @@ dependencies {
     antlr "org.antlr:antlr4:4.7.1"
 
     compile "org.antlr:antlr4-runtime:4.7.1"
-    compile group: 'com.google.guava', name: 'guava', version:'23.0'
-    compile group: 'org.elasticsearch', name: 'elasticsearch-x-content', version:"${es_version}"
-    compile group: 'org.json', name: 'json', version:'20180813'
+    compile group: 'com.google.guava', name: 'guava', version: '23.0'
+    compile group: 'org.elasticsearch', name: 'elasticsearch-x-content', version: "${es_version}"
+    compile group: 'org.json', name: 'json', version: '20180813'
     compile group: 'org.springframework', name: 'spring-context', version: '5.2.5.RELEASE'
     compile group: 'org.springframework', name: 'spring-beans', version: '5.2.5.RELEASE'
     compile project(':common')
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLService.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLService.java
index 88543ab481..0c3e437c68 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLService.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLService.java
@@ -15,14 +15,13 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine.QueryResponse;
+
 import com.amazon.opendistroforelasticsearch.sql.analysis.AnalysisContext;
 import com.amazon.opendistroforelasticsearch.sql.analysis.Analyzer;
-import com.amazon.opendistroforelasticsearch.sql.analysis.ExpressionAnalyzer;
 import com.amazon.opendistroforelasticsearch.sql.ast.tree.UnresolvedPlan;
 import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
 import com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine;
-import com.amazon.opendistroforelasticsearch.sql.expression.DSL;
-import com.amazon.opendistroforelasticsearch.sql.expression.function.BuiltinFunctionRepository;
 import com.amazon.opendistroforelasticsearch.sql.planner.Planner;
 import com.amazon.opendistroforelasticsearch.sql.planner.logical.LogicalPlan;
 import com.amazon.opendistroforelasticsearch.sql.planner.physical.PhysicalPlan;
@@ -34,36 +33,37 @@
 import lombok.RequiredArgsConstructor;
 import org.antlr.v4.runtime.tree.ParseTree;
 
-import java.util.HashMap;
-
-import static com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine.QueryResponse;
-
 @RequiredArgsConstructor
 public class PPLService {
-    private final PPLSyntaxParser parser;
+  private final PPLSyntaxParser parser;
 
-    private final Analyzer analyzer;
+  private final Analyzer analyzer;
 
-    private final StorageEngine storageEngine;
+  private final StorageEngine storageEngine;
 
-    private final ExecutionEngine executionEngine;
+  private final ExecutionEngine executionEngine;
 
-    public void execute(PPLQueryRequest request, ResponseListener<QueryResponse> listener) {
-        try {
-            // 1.Parse query and convert parse tree (CST) to abstract syntax tree (AST)
-            ParseTree cst = parser.analyzeSyntax(request.getRequest());
-            UnresolvedPlan ast = cst.accept(new AstBuilder(new AstExpressionBuilder()));
+  /**
+   * Execute the {@link PPLQueryRequest}, using {@link ResponseListener} to get response.
+   * @param request {@link PPLQueryRequest}
+   * @param listener {@link ResponseListener}
+   */
+  public void execute(PPLQueryRequest request, ResponseListener<QueryResponse> listener) {
+    try {
+      // 1.Parse query and convert parse tree (CST) to abstract syntax tree (AST)
+      ParseTree cst = parser.analyzeSyntax(request.getRequest());
+      UnresolvedPlan ast = cst.accept(new AstBuilder(new AstExpressionBuilder()));
 
-            // 2.Analyze abstract syntax to generate logical plan
-            LogicalPlan logicalPlan = analyzer.analyze(ast, new AnalysisContext());
+      // 2.Analyze abstract syntax to generate logical plan
+      LogicalPlan logicalPlan = analyzer.analyze(ast, new AnalysisContext());
 
-            // 3.Generate optimal physical plan from logical plan
-            PhysicalPlan physicalPlan = new Planner(storageEngine).plan(logicalPlan);
+      // 3.Generate optimal physical plan from logical plan
+      PhysicalPlan physicalPlan = new Planner(storageEngine).plan(logicalPlan);
 
-            // 4.Execute physical plan and send response
-            executionEngine.execute(physicalPlan, listener);
-        } catch (Exception e) {
-            listener.onFailure(e);
-        }
+      // 4.Execute physical plan and send response
+      executionEngine.execute(physicalPlan, listener);
+    } catch (Exception e) {
+      listener.onFailure(e);
     }
+  }
 }
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParser.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParser.java
index 9bffa41b9d..c638ae7ab1 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParser.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParser.java
@@ -24,22 +24,25 @@
 import org.antlr.v4.runtime.tree.ParseTree;
 
 /**
- * PPL Syntax Parser
+ * PPL Syntax Parser.
  */
 public class PPLSyntaxParser {
-    public ParseTree analyzeSyntax(String query) {
-        OpenDistroPPLParser parser = createParser(createLexer(query));
-        parser.addErrorListener(new SyntaxAnalysisErrorListener());
-        return parser.root();
-    }
+  /**
+   * Analyze the query syntax.
+   */
+  public ParseTree analyzeSyntax(String query) {
+    OpenDistroPPLParser parser = createParser(createLexer(query));
+    parser.addErrorListener(new SyntaxAnalysisErrorListener());
+    return parser.root();
+  }
 
-    private OpenDistroPPLParser createParser(Lexer lexer) {
-        return new OpenDistroPPLParser(
-                new CommonTokenStream(lexer));
-    }
+  private OpenDistroPPLParser createParser(Lexer lexer) {
+    return new OpenDistroPPLParser(
+        new CommonTokenStream(lexer));
+  }
 
-    private OpenDistroPPLLexer createLexer(String query) {
-        return new OpenDistroPPLLexer(
-                new CaseInsensitiveCharStream(query));
-    }
+  private OpenDistroPPLLexer createLexer(String query) {
+    return new OpenDistroPPLLexer(
+        new CaseInsensitiveCharStream(query));
+  }
 }
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfig.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfig.java
index 8e5aa33ddc..f1a6e3aae0 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfig.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfig.java
@@ -32,23 +32,23 @@
 @Import({ExpressionConfig.class})
 public class PPLServiceConfig {
 
-    @Autowired
-    private StorageEngine storageEngine;
+  @Autowired
+  private StorageEngine storageEngine;
 
-    @Autowired
-    private ExecutionEngine executionEngine;
+  @Autowired
+  private ExecutionEngine executionEngine;
 
-    @Autowired
-    private BuiltinFunctionRepository functionRepository;
+  @Autowired
+  private BuiltinFunctionRepository functionRepository;
 
-    @Bean
-    public Analyzer analyzer() {
-        return new Analyzer(new ExpressionAnalyzer(functionRepository), storageEngine);
-    }
+  @Bean
+  public Analyzer analyzer() {
+    return new Analyzer(new ExpressionAnalyzer(functionRepository), storageEngine);
+  }
 
-    @Bean
-    public PPLService pplService() {
-        return new PPLService(new PPLSyntaxParser(), analyzer(), storageEngine, executionEngine);
-    }
+  @Bean
+  public PPLService pplService() {
+    return new PPLService(new PPLSyntaxParser(), analyzer(), storageEngine, executionEngine);
+  }
 
 }
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequest.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequest.java
index 9b83a8d43d..9bb348fd43 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequest.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequest.java
@@ -15,18 +15,17 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.domain;
 
-
 import lombok.RequiredArgsConstructor;
 import org.json.JSONObject;
 
 @RequiredArgsConstructor
 public class PPLQueryRequest {
-    public static final PPLQueryRequest NULL = new PPLQueryRequest("", null);
+  public static final PPLQueryRequest NULL = new PPLQueryRequest("", null);
 
-    private final String pplQuery;
-    private final JSONObject jsonContent;
+  private final String pplQuery;
+  private final JSONObject jsonContent;
 
-    public String getRequest() {
-        return pplQuery;
-    }
+  public String getRequest() {
+    return pplQuery;
+  }
 }
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilder.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilder.java
index b989539eab..059b28e066 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilder.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilder.java
@@ -15,6 +15,19 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.parser;
 
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.DedupCommandContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.EvalCommandContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.FieldsCommandContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.FromClauseContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.PplStatementContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.RenameCommandContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SearchFilterFromContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SearchFromContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SearchFromFilterContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SortCommandContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.StatsCommandContext;
+import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.WhereCommandContext;
+
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Field;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Let;
 import com.amazon.opendistroforelasticsearch.sql.ast.expression.Map;
@@ -32,181 +45,187 @@
 import com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParserBaseVisitor;
 import com.amazon.opendistroforelasticsearch.sql.ppl.utils.ArgumentFactory;
 import com.google.common.collect.ImmutableList;
-import lombok.RequiredArgsConstructor;
-import org.antlr.v4.runtime.tree.ParseTree;
-
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
-
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.DedupCommandContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.EvalCommandContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.FieldsCommandContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.FromClauseContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.PplStatementContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.RenameCommandContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SearchFilterFromContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SearchFromContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SearchFromFilterContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SortCommandContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.StatsCommandContext;
-import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.WhereCommandContext;
+import lombok.RequiredArgsConstructor;
+import org.antlr.v4.runtime.tree.ParseTree;
 
 /**
- * Class of building the AST
+ * Class of building the AST.
  * Refines the visit path and build the AST nodes
  */
 @RequiredArgsConstructor
 public class AstBuilder extends OpenDistroPPLParserBaseVisitor<UnresolvedPlan> {
-    private final AstExpressionBuilder expressionBuilder;
-
-    @Override
-    public UnresolvedPlan visitPplStatement(PplStatementContext ctx) {
-        UnresolvedPlan search = visit(ctx.searchCommand());
-        return ctx.commands()
-                .stream()
-                .map(this::visit)
-                .reduce(search, (r, e) -> e.attach(r));
-    }
-
-    /** Search command */
-    @Override
-    public UnresolvedPlan visitSearchFrom(SearchFromContext ctx) {
-        return visitFromClause(ctx.fromClause());
-    }
-
-    @Override
-    public UnresolvedPlan visitSearchFromFilter(SearchFromFilterContext ctx) {
-        return new Filter(visitExpression(ctx.logicalExpression())).attach(visit(ctx.fromClause()));
-    }
-
-    @Override
-    public UnresolvedPlan visitSearchFilterFrom(SearchFilterFromContext ctx) {
-        return new Filter(visitExpression(ctx.logicalExpression())).attach(visit(ctx.fromClause()));
-    }
-
-    /** Where command */
-    @Override
-    public UnresolvedPlan visitWhereCommand(WhereCommandContext ctx) {
-        return new Filter(visitExpression(ctx.logicalExpression()));
-    }
-
-    /** Fields command */
-    @Override
-    public UnresolvedPlan visitFieldsCommand(FieldsCommandContext ctx) {
-        return new Project(
-                ctx.wcFieldList()
-                        .wcFieldExpression()
-                        .stream()
-                        .map(this::visitExpression)
-                        .collect(Collectors.toList()),
-                ArgumentFactory.getArgumentList(ctx)
-        );
-    }
-
-    /** Rename command */
-    @Override
-    public UnresolvedPlan visitRenameCommand(RenameCommandContext ctx) {
-        return new Rename(
-                new ArrayList<>(
-                        Collections.singletonList(
-                                new Map(
-                                        visitExpression(ctx.orignalField),
-                                        visitExpression(ctx.renamedField)
-                                )
-                        )
+  private final AstExpressionBuilder expressionBuilder;
+
+  @Override
+  public UnresolvedPlan visitPplStatement(PplStatementContext ctx) {
+    UnresolvedPlan search = visit(ctx.searchCommand());
+    return ctx.commands()
+        .stream()
+        .map(this::visit)
+        .reduce(search, (r, e) -> e.attach(r));
+  }
+
+  /**
+   * Search command.
+   */
+  @Override
+  public UnresolvedPlan visitSearchFrom(SearchFromContext ctx) {
+    return visitFromClause(ctx.fromClause());
+  }
+
+  @Override
+  public UnresolvedPlan visitSearchFromFilter(SearchFromFilterContext ctx) {
+    return new Filter(visitExpression(ctx.logicalExpression())).attach(visit(ctx.fromClause()));
+  }
+
+  @Override
+  public UnresolvedPlan visitSearchFilterFrom(SearchFilterFromContext ctx) {
+    return new Filter(visitExpression(ctx.logicalExpression())).attach(visit(ctx.fromClause()));
+  }
+
+  /**
+   * Where command.
+   */
+  @Override
+  public UnresolvedPlan visitWhereCommand(WhereCommandContext ctx) {
+    return new Filter(visitExpression(ctx.logicalExpression()));
+  }
+
+  /**
+   * Fields command.
+   */
+  @Override
+  public UnresolvedPlan visitFieldsCommand(FieldsCommandContext ctx) {
+    return new Project(
+        ctx.wcFieldList()
+            .wcFieldExpression()
+            .stream()
+            .map(this::visitExpression)
+            .collect(Collectors.toList()),
+        ArgumentFactory.getArgumentList(ctx)
+    );
+  }
+
+  /**
+   * Rename command.
+   */
+  @Override
+  public UnresolvedPlan visitRenameCommand(RenameCommandContext ctx) {
+    return new Rename(
+        new ArrayList<>(
+            Collections.singletonList(
+                new Map(
+                    visitExpression(ctx.orignalField),
+                    visitExpression(ctx.renamedField)
                 )
-        );
-    }
-
-    /** Stats command */
-    @Override
-    public UnresolvedPlan visitStatsCommand(StatsCommandContext ctx) {
-        ImmutableList.Builder<UnresolvedExpression> aggListBuilder = new ImmutableList.Builder<>();
-        ImmutableList.Builder<Map> renameListBuilder = new ImmutableList.Builder<>();
-        for (OpenDistroPPLParser.StatsAggTermContext aggCtx : ctx.statsAggTerm()) {
-            UnresolvedExpression aggExpression = visitExpression(aggCtx.statsFunction());
-            aggListBuilder.add(aggExpression);
-            if (aggCtx.alias != null) {
-                renameListBuilder
-                        .add(new Map(aggExpression, visitExpression(aggCtx.alias)));
-            }
-        }
-        List<UnresolvedExpression> groupList = ctx.byClause() == null ? Collections.emptyList() :
-                ctx.byClause()
-                        .fieldList()
-                        .fieldExpression()
-                        .stream()
-                        .map(this::visitExpression)
-                        .collect(Collectors.toList());
-        Aggregation aggregation = new Aggregation(
-                aggListBuilder.build(),
-                Collections.emptyList(),
-                groupList,
-                ArgumentFactory.getArgumentList(ctx)
-        );
-        List<Map> renameList = renameListBuilder.build();
-        return renameList.isEmpty() ? aggregation : new Rename(renameList, aggregation);
-    }
-
-    /** Dedup command */
-    @Override
-    public UnresolvedPlan visitDedupCommand(DedupCommandContext ctx) {
-        return new Dedupe(
-                ArgumentFactory.getArgumentList(ctx),
-                ctx.fieldList()
-                        .fieldExpression()
-                        .stream()
-                        .map(field -> (Field) visitExpression(field))
-                        .collect(Collectors.toList())
-        );
-    }
-
-    /** Sort command */
-    @Override
-    public UnresolvedPlan visitSortCommand(SortCommandContext ctx) {
-        return new Sort(
-                ArgumentFactory.getArgumentList(ctx),
-                ctx.sortbyClause()
-                        .sortField()
-                        .stream()
-                        .map(sort -> (Field) visitExpression(sort))
-                        .collect(Collectors.toList())
-        );
+            )
+        )
+    );
+  }
+
+  /**
+   * Stats command.
+   */
+  @Override
+  public UnresolvedPlan visitStatsCommand(StatsCommandContext ctx) {
+    ImmutableList.Builder<UnresolvedExpression> aggListBuilder = new ImmutableList.Builder<>();
+    ImmutableList.Builder<Map> renameListBuilder = new ImmutableList.Builder<>();
+    for (OpenDistroPPLParser.StatsAggTermContext aggCtx : ctx.statsAggTerm()) {
+      UnresolvedExpression aggExpression = visitExpression(aggCtx.statsFunction());
+      aggListBuilder.add(aggExpression);
+      if (aggCtx.alias != null) {
+        renameListBuilder
+            .add(new Map(aggExpression, visitExpression(aggCtx.alias)));
+      }
     }
-
-    /** Eval command */
-    @Override
-    public UnresolvedPlan visitEvalCommand(EvalCommandContext ctx) {
-        return new Eval(
-                ctx.evalExpression()
-                        .stream()
-                        .map(ct -> (Let) visitExpression(ct))
-                        .collect(Collectors.toList())
-        );
-    }
-
-    /** From clause */
-    @Override
-    public UnresolvedPlan visitFromClause(FromClauseContext ctx) {
-        return new Relation(visitExpression(ctx.tableSource().qualifiedName()));
-    }
-
-    /** Navigate to & build AST expression */
-    private UnresolvedExpression visitExpression(ParseTree tree) {
-        return expressionBuilder.visit(tree);
-    }
-
-    /**
-     * Simply return non-default value for now
-     */
-    @Override
-    protected UnresolvedPlan aggregateResult(UnresolvedPlan aggregate, UnresolvedPlan nextResult) {
-        if (nextResult != defaultResult()) {
-            return nextResult;
-        }
-        return aggregate;
+    List<UnresolvedExpression> groupList = ctx.byClause() == null ? Collections.emptyList() :
+        ctx.byClause()
+            .fieldList()
+            .fieldExpression()
+            .stream()
+            .map(this::visitExpression)
+            .collect(Collectors.toList());
+    Aggregation aggregation = new Aggregation(
+        aggListBuilder.build(),
+        Collections.emptyList(),
+        groupList,
+        ArgumentFactory.getArgumentList(ctx)
+    );
+    List<Map> renameList = renameListBuilder.build();
+    return renameList.isEmpty() ? aggregation : new Rename(renameList, aggregation);
+  }
+
+  /**
+   * Dedup command.
+   */
+  @Override
+  public UnresolvedPlan visitDedupCommand(DedupCommandContext ctx) {
+    return new Dedupe(
+        ArgumentFactory.getArgumentList(ctx),
+        ctx.fieldList()
+            .fieldExpression()
+            .stream()
+            .map(field -> (Field) visitExpression(field))
+            .collect(Collectors.toList())
+    );
+  }
+
+  /**
+   * Sort command.
+   */
+  @Override
+  public UnresolvedPlan visitSortCommand(SortCommandContext ctx) {
+    return new Sort(
+        ArgumentFactory.getArgumentList(ctx),
+        ctx.sortbyClause()
+            .sortField()
+            .stream()
+            .map(sort -> (Field) visitExpression(sort))
+            .collect(Collectors.toList())
+    );
+  }
+
+  /**
+   * Eval command.
+   */
+  @Override
+  public UnresolvedPlan visitEvalCommand(EvalCommandContext ctx) {
+    return new Eval(
+        ctx.evalExpression()
+            .stream()
+            .map(ct -> (Let) visitExpression(ct))
+            .collect(Collectors.toList())
+    );
+  }
+
+  /**
+   * From clause.
+   */
+  @Override
+  public UnresolvedPlan visitFromClause(FromClauseContext ctx) {
+    return new Relation(visitExpression(ctx.tableSource().qualifiedName()));
+  }
+
+  /**
+   * Navigate to & build AST expression.
+   */
+  private UnresolvedExpression visitExpression(ParseTree tree) {
+    return expressionBuilder.visit(tree);
+  }
+
+  /**
+   * Simply return non-default value for now.
+   */
+  @Override
+  protected UnresolvedPlan aggregateResult(UnresolvedPlan aggregate, UnresolvedPlan nextResult) {
+    if (nextResult != defaultResult()) {
+      return nextResult;
     }
+    return aggregate;
+  }
 
 }
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilder.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilder.java
index c5631ddfdd..05556fbc3f 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilder.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilder.java
@@ -15,29 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.parser;
 
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Argument;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Compare;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Field;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Let;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.QualifiedName;
-import com.amazon.opendistroforelasticsearch.sql.common.utils.StringUtils;
-import com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParserBaseVisitor;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.AggregateFunction;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.And;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.DataType;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.UnresolvedExpression;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Function;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.In;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Literal;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Not;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Or;
-import com.amazon.opendistroforelasticsearch.sql.ppl.utils.ArgumentFactory;
-
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.stream.Collectors;
-import org.antlr.v4.runtime.ParserRuleContext;
-
 import static com.amazon.opendistroforelasticsearch.sql.common.utils.StringUtils.unquoteIdentifier;
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.BinaryArithmeticContext;
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.BooleanLiteralContext;
@@ -59,148 +36,184 @@
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.WcFieldExpressionContext;
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.WcQualifiedNameContext;
 
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.AggregateFunction;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.And;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Argument;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Compare;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.DataType;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Field;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Function;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.In;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Let;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Literal;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Not;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Or;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.QualifiedName;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.UnresolvedExpression;
+import com.amazon.opendistroforelasticsearch.sql.common.utils.StringUtils;
+import com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParserBaseVisitor;
+import com.amazon.opendistroforelasticsearch.sql.ppl.utils.ArgumentFactory;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.stream.Collectors;
+import org.antlr.v4.runtime.ParserRuleContext;
+
 /**
- * Class of building AST Expression nodes
+ * Class of building AST Expression nodes.
  */
 public class AstExpressionBuilder extends OpenDistroPPLParserBaseVisitor<UnresolvedExpression> {
-    /** Logical expression excluding boolean, eval, comparison */
-    @Override
-    public UnresolvedExpression visitLogicalNot(LogicalNotContext ctx) {
-        return new Not(visit(ctx.logicalExpression()));
-    }
-
-    @Override
-    public UnresolvedExpression visitLogicalOr(LogicalOrContext ctx) {
-        return new Or(visit(ctx.left), visit(ctx.right));
-    }
-
-    @Override
-    public UnresolvedExpression visitLogicalAnd(LogicalAndContext ctx) {
-        return new And(visit(ctx.left), visit(ctx.right));
-    }
-
-
-    /** Eval expression */
-    @Override
-    public UnresolvedExpression visitEvalExpression(EvalExpressionContext ctx) {
-        Field field = (Field) visit(ctx.fieldExpression());
-        UnresolvedExpression evalFunctionCall = visit(ctx.expression());
-        return new Let(field, evalFunctionCall);
-    }
-
-    /** Comparison expression */
-    @Override
-    public UnresolvedExpression visitCompareExpr(CompareExprContext ctx) {
-        UnresolvedExpression right = ctx.field != null ? visit(ctx.field) : visit(ctx.literal);
-        return new Compare(ctx.comparisonOperator().getText(), visit(ctx.left), right);
-    }
-
-    @Override
-    public UnresolvedExpression visitInExpr(InExprContext ctx) {
-        return new In(
-                visit(ctx.fieldExpression()),
-                ctx.valueList()
-                        .literalValue()
-                        .stream()
-                        .map(this::visitLiteralValue)
-                        .collect(Collectors.toList()));
-    }
-
-    @Override
-    public UnresolvedExpression visitBinaryArithmetic(BinaryArithmeticContext ctx) {
-        return new Function(
-                ctx.binaryOperator().getText(),
-                Arrays.asList(
-                        ctx.leftField != null ? visit(ctx.leftField) : visit(ctx.leftValue),
-                        ctx.rightField != null ? visit(ctx.rightField) : visit(ctx.rightValue)
-                )
-        );
-    }
-
-    /** Field expression */
-    @Override
-    public UnresolvedExpression visitFieldExpression(FieldExpressionContext ctx) {
-        return new Field((QualifiedName) visit(ctx.qualifiedName()));
-    }
-
-    @Override
-    public UnresolvedExpression visitWcFieldExpression(WcFieldExpressionContext ctx) {
-        return new Field((QualifiedName) visit(ctx.wcQualifiedName()));
-    }
-
-    @Override
-    public UnresolvedExpression visitSortField(SortFieldContext ctx) {
-        return new Field(
-                ctx.sortFieldExpression().fieldExpression().getText(),
-                ArgumentFactory.getArgumentList(ctx)
-        );
-    }
-
-    /** Aggregation function */
-    @Override
-    public UnresolvedExpression visitStatsFunctionCall(StatsFunctionCallContext ctx) {
-        return new AggregateFunction(ctx.statsFunctionName().getText(), visit(ctx.fieldExpression()));
-    }
-
-    @Override
-    public UnresolvedExpression visitPercentileAggFunction(PercentileAggFunctionContext ctx) {
-        return new AggregateFunction(ctx.PERCENTILE().getText(), visit(ctx.aggField),
-                Collections.singletonList(new Argument("rank", (Literal) visit(ctx.value))));
-    }
-
-    /** Eval function */
-    @Override
-    public UnresolvedExpression visitEvalFunctionCall(EvalFunctionCallContext ctx) {
-        return new Function(
-                ctx.evalFunctionName().getText(),
-                ctx.functionArgs()
-                        .functionArg()
-                        .stream()
-                        .map(this::visitFunctionArg)
-                        .collect(Collectors.toList()));
-    }
-
-    /** Literal and value */
-    @Override
-    public UnresolvedExpression visitQualifiedName(QualifiedNameContext ctx) {
-        return new QualifiedName(
-                ctx.ident()
-                        .stream()
-                        .map(ParserRuleContext::getText)
-                        .map(StringUtils::unquoteIdentifier)
-                        .collect(Collectors.toList())
-        );
-    }
-
-    @Override
-    public UnresolvedExpression visitWcQualifiedName(WcQualifiedNameContext ctx) {
-        return new QualifiedName(
-                ctx.wildcard()
-                        .stream()
-                        .map(ParserRuleContext::getText)
-                        .map(StringUtils::unquoteIdentifier)
-                        .collect(Collectors.toList())
-        );
-    }
-
-    @Override
-    public UnresolvedExpression visitStringLiteral(StringLiteralContext ctx) {
-        return new Literal(unquoteIdentifier(ctx.getText()), DataType.STRING);
-    }
-
-    @Override
-    public UnresolvedExpression visitIntegerLiteral(IntegerLiteralContext ctx) {
-        return new Literal(Integer.valueOf(ctx.getText()), DataType.INTEGER);
-    }
-
-    @Override
-    public UnresolvedExpression visitDecimalLiteral(DecimalLiteralContext ctx) {
-        return new Literal(Double.valueOf(ctx.getText()), DataType.DOUBLE);
-    }
-
-    @Override
-    public UnresolvedExpression visitBooleanLiteral(BooleanLiteralContext ctx) {
-        return new Literal(Boolean.valueOf(ctx.getText()), DataType.BOOLEAN);
-    }
+  /**
+   * Logical expression excluding boolean, eval, comparison.
+   */
+  @Override
+  public UnresolvedExpression visitLogicalNot(LogicalNotContext ctx) {
+    return new Not(visit(ctx.logicalExpression()));
+  }
+
+  @Override
+  public UnresolvedExpression visitLogicalOr(LogicalOrContext ctx) {
+    return new Or(visit(ctx.left), visit(ctx.right));
+  }
+
+  @Override
+  public UnresolvedExpression visitLogicalAnd(LogicalAndContext ctx) {
+    return new And(visit(ctx.left), visit(ctx.right));
+  }
+
+
+  /**
+   * Eval expression.
+   */
+  @Override
+  public UnresolvedExpression visitEvalExpression(EvalExpressionContext ctx) {
+    Field field = (Field) visit(ctx.fieldExpression());
+    UnresolvedExpression evalFunctionCall = visit(ctx.expression());
+    return new Let(field, evalFunctionCall);
+  }
+
+  /**
+   * Comparison expression.
+   */
+  @Override
+  public UnresolvedExpression visitCompareExpr(CompareExprContext ctx) {
+    UnresolvedExpression right = ctx.field != null ? visit(ctx.field) : visit(ctx.literal);
+    return new Compare(ctx.comparisonOperator().getText(), visit(ctx.left), right);
+  }
+
+  @Override
+  public UnresolvedExpression visitInExpr(InExprContext ctx) {
+    return new In(
+        visit(ctx.fieldExpression()),
+        ctx.valueList()
+            .literalValue()
+            .stream()
+            .map(this::visitLiteralValue)
+            .collect(Collectors.toList()));
+  }
+
+  @Override
+  public UnresolvedExpression visitBinaryArithmetic(BinaryArithmeticContext ctx) {
+    return new Function(
+        ctx.binaryOperator().getText(),
+        Arrays.asList(
+            ctx.leftField != null ? visit(ctx.leftField) : visit(ctx.leftValue),
+            ctx.rightField != null ? visit(ctx.rightField) : visit(ctx.rightValue)
+        )
+    );
+  }
+
+  /**
+   * Field expression.
+   */
+  @Override
+  public UnresolvedExpression visitFieldExpression(FieldExpressionContext ctx) {
+    return new Field((QualifiedName) visit(ctx.qualifiedName()));
+  }
+
+  @Override
+  public UnresolvedExpression visitWcFieldExpression(WcFieldExpressionContext ctx) {
+    return new Field((QualifiedName) visit(ctx.wcQualifiedName()));
+  }
+
+  @Override
+  public UnresolvedExpression visitSortField(SortFieldContext ctx) {
+    return new Field(
+        ctx.sortFieldExpression().fieldExpression().getText(),
+        ArgumentFactory.getArgumentList(ctx)
+    );
+  }
+
+  /**
+   * Aggregation function.
+   */
+  @Override
+  public UnresolvedExpression visitStatsFunctionCall(StatsFunctionCallContext ctx) {
+    return new AggregateFunction(ctx.statsFunctionName().getText(), visit(ctx.fieldExpression()));
+  }
+
+  @Override
+  public UnresolvedExpression visitPercentileAggFunction(PercentileAggFunctionContext ctx) {
+    return new AggregateFunction(ctx.PERCENTILE().getText(), visit(ctx.aggField),
+        Collections.singletonList(new Argument("rank", (Literal) visit(ctx.value))));
+  }
+
+  /**
+   * Eval function.
+   */
+  @Override
+  public UnresolvedExpression visitEvalFunctionCall(EvalFunctionCallContext ctx) {
+    return new Function(
+        ctx.evalFunctionName().getText(),
+        ctx.functionArgs()
+            .functionArg()
+            .stream()
+            .map(this::visitFunctionArg)
+            .collect(Collectors.toList()));
+  }
+
+  /**
+   * Literal and value.
+   */
+  @Override
+  public UnresolvedExpression visitQualifiedName(QualifiedNameContext ctx) {
+    return new QualifiedName(
+        ctx.ident()
+            .stream()
+            .map(ParserRuleContext::getText)
+            .map(StringUtils::unquoteIdentifier)
+            .collect(Collectors.toList())
+    );
+  }
+
+  @Override
+  public UnresolvedExpression visitWcQualifiedName(WcQualifiedNameContext ctx) {
+    return new QualifiedName(
+        ctx.wildcard()
+            .stream()
+            .map(ParserRuleContext::getText)
+            .map(StringUtils::unquoteIdentifier)
+            .collect(Collectors.toList())
+    );
+  }
+
+  @Override
+  public UnresolvedExpression visitStringLiteral(StringLiteralContext ctx) {
+    return new Literal(unquoteIdentifier(ctx.getText()), DataType.STRING);
+  }
+
+  @Override
+  public UnresolvedExpression visitIntegerLiteral(IntegerLiteralContext ctx) {
+    return new Literal(Integer.valueOf(ctx.getText()), DataType.INTEGER);
+  }
+
+  @Override
+  public UnresolvedExpression visitDecimalLiteral(DecimalLiteralContext ctx) {
+    return new Literal(Double.valueOf(ctx.getText()), DataType.DOUBLE);
+  }
+
+  @Override
+  public UnresolvedExpression visitBooleanLiteral(BooleanLiteralContext ctx) {
+    return new Literal(Boolean.valueOf(ctx.getText()), DataType.BOOLEAN);
+  }
 
 }
diff --git a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactory.java b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactory.java
index 2f4b8e1e52..aaa839d0b2 100644
--- a/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactory.java
+++ b/ppl/src/main/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactory.java
@@ -15,14 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.utils;
 
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Argument;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.DataType;
-import com.amazon.opendistroforelasticsearch.sql.ast.expression.Literal;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import org.antlr.v4.runtime.ParserRuleContext;
-
 import static com.amazon.opendistroforelasticsearch.sql.common.utils.StringUtils.unquoteIdentifier;
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.BooleanLiteralContext;
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.DedupCommandContext;
@@ -32,103 +24,123 @@
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.SortFieldContext;
 import static com.amazon.opendistroforelasticsearch.sql.ppl.antlr.parser.OpenDistroPPLParser.StatsCommandContext;
 
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Argument;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.DataType;
+import com.amazon.opendistroforelasticsearch.sql.ast.expression.Literal;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import org.antlr.v4.runtime.ParserRuleContext;
+
 
 /**
- * Util class to get all arguments as a list from the PPL command
+ * Util class to get all arguments as a list from the PPL command.
  */
 public class ArgumentFactory {
 
-    /**
-     * @param ctx FieldsCommandContext instance
-     * @return the list of arguments fetched from the fields command
-     */
-    public static List<Argument> getArgumentList(FieldsCommandContext ctx) {
-        return Collections.singletonList(
-                ctx.MINUS() != null
-                        ? new Argument("exclude", new Literal(true, DataType.BOOLEAN))
-                        : new Argument("exclude", new Literal(false, DataType.BOOLEAN))
-        );
-    }
+  /**
+   * Get list of {@link Argument}.
+   *
+   * @param ctx FieldsCommandContext instance
+   * @return the list of arguments fetched from the fields command
+   */
+  public static List<Argument> getArgumentList(FieldsCommandContext ctx) {
+    return Collections.singletonList(
+        ctx.MINUS() != null
+            ? new Argument("exclude", new Literal(true, DataType.BOOLEAN))
+            : new Argument("exclude", new Literal(false, DataType.BOOLEAN))
+    );
+  }
 
-    /**
-     * @param ctx StatsCommandContext instance
-     * @return the list of arguments fetched from the stats command
-     */
-    public static List<Argument> getArgumentList(StatsCommandContext ctx) {
-        return Arrays.asList(
-                ctx.partitions != null
-                    ? new Argument("partitions", getArgumentValue(ctx.partitions))
-                    : new Argument("partitions", new Literal(1, DataType.INTEGER)),
-                ctx.allnum != null
-                    ? new Argument("allnum", getArgumentValue(ctx.allnum))
-                    : new Argument("allnum", new Literal(false, DataType.BOOLEAN)),
-                ctx.delim != null
-                    ? new Argument("delim", getArgumentValue(ctx.delim))
-                    : new Argument("delim", new Literal(" ", DataType.STRING)),
-                ctx.dedupsplit != null
-                    ? new Argument("dedupsplit", getArgumentValue(ctx.dedupsplit))
-                    : new Argument("dedupsplit", new Literal(false, DataType.BOOLEAN))
-        );
-    }
+  /**
+   * Get list of {@link Argument}.
+   *
+   * @param ctx StatsCommandContext instance
+   * @return the list of arguments fetched from the stats command
+   */
+  public static List<Argument> getArgumentList(StatsCommandContext ctx) {
+    return Arrays.asList(
+        ctx.partitions != null
+            ? new Argument("partitions", getArgumentValue(ctx.partitions))
+            : new Argument("partitions", new Literal(1, DataType.INTEGER)),
+        ctx.allnum != null
+            ? new Argument("allnum", getArgumentValue(ctx.allnum))
+            : new Argument("allnum", new Literal(false, DataType.BOOLEAN)),
+        ctx.delim != null
+            ? new Argument("delim", getArgumentValue(ctx.delim))
+            : new Argument("delim", new Literal(" ", DataType.STRING)),
+        ctx.dedupsplit != null
+            ? new Argument("dedupsplit", getArgumentValue(ctx.dedupsplit))
+            : new Argument("dedupsplit", new Literal(false, DataType.BOOLEAN))
+    );
+  }
 
-    /**
-     * @param ctx DedupCommandContext instance
-     * @return the list of arguments fetched from the dedup command
-     */
-    public static List<Argument> getArgumentList(DedupCommandContext ctx) {
-        return Arrays.asList(
-                ctx.number != null
-                    ? new Argument("number", getArgumentValue(ctx.number))
-                    : new Argument("number", new Literal(1, DataType.INTEGER)),
-                ctx.keepempty != null
-                    ? new Argument("keepempty", getArgumentValue(ctx.keepempty))
-                    : new Argument("keepempty", new Literal(false, DataType.BOOLEAN)),
-                ctx.consecutive != null
-                    ? new Argument("consecutive", getArgumentValue(ctx.consecutive))
-                    : new Argument("consecutive", new Literal(false, DataType.BOOLEAN))
-        );
-    }
+  /**
+   * Get list of {@link Argument}.
+   *
+   * @param ctx DedupCommandContext instance
+   * @return the list of arguments fetched from the dedup command
+   */
+  public static List<Argument> getArgumentList(DedupCommandContext ctx) {
+    return Arrays.asList(
+        ctx.number != null
+            ? new Argument("number", getArgumentValue(ctx.number))
+            : new Argument("number", new Literal(1, DataType.INTEGER)),
+        ctx.keepempty != null
+            ? new Argument("keepempty", getArgumentValue(ctx.keepempty))
+            : new Argument("keepempty", new Literal(false, DataType.BOOLEAN)),
+        ctx.consecutive != null
+            ? new Argument("consecutive", getArgumentValue(ctx.consecutive))
+            : new Argument("consecutive", new Literal(false, DataType.BOOLEAN))
+    );
+  }
 
-    /**
-     * @param ctx SortCommandContext instance
-     * @return the list of arguments fetched from the sort command
-     */
-    public static List<Argument> getArgumentList(SortCommandContext ctx) {
-        return Arrays.asList(
-                ctx.count != null
-                    ? new Argument("count", getArgumentValue(ctx.count))
-                    : new Argument("count", new Literal(1000, DataType.INTEGER)),
-                ctx.D() != null || ctx.DESC() != null
-                    ? new Argument("desc", new Literal(true, DataType.BOOLEAN))
-                    : new Argument("desc", new Literal(false, DataType.BOOLEAN))
-        );
-    }
+  /**
+   * Get list of {@link Argument}.
+   *
+   * @param ctx SortCommandContext instance
+   * @return the list of arguments fetched from the sort command
+   */
+  public static List<Argument> getArgumentList(SortCommandContext ctx) {
+    return Arrays.asList(
+        ctx.count != null
+            ? new Argument("count", getArgumentValue(ctx.count))
+            : new Argument("count", new Literal(1000, DataType.INTEGER)),
+        ctx.D() != null || ctx.DESC() != null
+            ? new Argument("desc", new Literal(true, DataType.BOOLEAN))
+            : new Argument("desc", new Literal(false, DataType.BOOLEAN))
+    );
+  }
 
-    /**
-     * @param ctx SortFieldContext instance
-     * @return the list of arguments fetched from the sort field in sort command
-     */
-    public static List<Argument> getArgumentList(SortFieldContext ctx) {
-        return Arrays.asList(
-                ctx.MINUS() != null
-                        ? new Argument("asc", new Literal(false, DataType.BOOLEAN))
-                        : new Argument("asc", new Literal(true, DataType.BOOLEAN)),
-                ctx.sortFieldExpression().AUTO() != null
-                        ? new Argument("type", new Literal("auto", DataType.STRING))
-                        : ctx.sortFieldExpression().IP() != null
-                        ? new Argument("type", new Literal("ip", DataType.STRING))
-                        : ctx.sortFieldExpression().NUM() != null
-                        ? new Argument("type", new Literal("num", DataType.STRING))
-                        : ctx.sortFieldExpression().STR() != null
-                        ? new Argument("type", new Literal("str", DataType.STRING))
-                        : new Argument("type", new Literal(null, DataType.NULL))
-        );
-    }
+  /**
+   * Get list of {@link Argument}.
+   *
+   * @param ctx SortFieldContext instance
+   * @return the list of arguments fetched from the sort field in sort command
+   */
+  public static List<Argument> getArgumentList(SortFieldContext ctx) {
+    return Arrays.asList(
+        ctx.MINUS() != null
+            ? new Argument("asc", new Literal(false, DataType.BOOLEAN))
+            : new Argument("asc", new Literal(true, DataType.BOOLEAN)),
+        ctx.sortFieldExpression().AUTO() != null
+            ? new Argument("type", new Literal("auto", DataType.STRING))
+            : ctx.sortFieldExpression().IP() != null
+            ? new Argument("type", new Literal("ip", DataType.STRING))
+            : ctx.sortFieldExpression().NUM() != null
+            ? new Argument("type", new Literal("num", DataType.STRING))
+            : ctx.sortFieldExpression().STR() != null
+            ? new Argument("type", new Literal("str", DataType.STRING))
+            : new Argument("type", new Literal(null, DataType.NULL))
+    );
+  }
 
-    private static Literal getArgumentValue(ParserRuleContext ctx) {
-        return ctx instanceof IntegerLiteralContext ? new Literal(Integer.parseInt(ctx.getText()), DataType.INTEGER)
-                : ctx instanceof BooleanLiteralContext ? new Literal(Boolean.valueOf(ctx.getText()), DataType.BOOLEAN)
-                : new Literal(unquoteIdentifier(ctx.getText()), DataType.STRING);
-    }
+  private static Literal getArgumentValue(ParserRuleContext ctx) {
+    return ctx instanceof IntegerLiteralContext
+        ? new Literal(Integer.parseInt(ctx.getText()), DataType.INTEGER)
+        : ctx instanceof BooleanLiteralContext
+        ? new Literal(Boolean.valueOf(ctx.getText()), DataType.BOOLEAN)
+        : new Literal(unquoteIdentifier(ctx.getText()), DataType.STRING);
+  }
 
 }
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLServiceTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLServiceTest.java
index b3176ab18e..b367c15c0a 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLServiceTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/PPLServiceTest.java
@@ -15,6 +15,10 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl;
 
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.doAnswer;
+import static org.mockito.Mockito.when;
+
 import com.amazon.opendistroforelasticsearch.sql.common.response.ResponseListener;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprType;
 import com.amazon.opendistroforelasticsearch.sql.executor.ExecutionEngine;
@@ -25,6 +29,7 @@
 import com.amazon.opendistroforelasticsearch.sql.storage.StorageEngine;
 import com.amazon.opendistroforelasticsearch.sql.storage.Table;
 import com.google.common.collect.ImmutableMap;
+import java.util.Collections;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
@@ -33,76 +38,74 @@
 import org.mockito.junit.MockitoJUnitRunner;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
-import java.util.Collections;
-
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.Mockito.doAnswer;
-import static org.mockito.Mockito.when;
-
 @RunWith(MockitoJUnitRunner.class)
 public class PPLServiceTest {
-    private AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
-
-    private PPLService pplService;
-
-    @Mock
-    private StorageEngine storageEngine;
-
-    @Mock
-    private ExecutionEngine executionEngine;
-
-    @Mock
-    private Table table;
-
-    @Mock
-    private PhysicalPlan plan;
-
-    @Before
-    public void setUp() {
-        when(table.getFieldTypes()).thenReturn(ImmutableMap.of("a", ExprType.INTEGER));
-        when(table.implement(any())).thenReturn(plan);
-        when(storageEngine.getTable(any())).thenReturn(table);
-
-        context.registerBean(StorageEngine.class, () -> storageEngine);
-        context.registerBean(ExecutionEngine.class, () -> executionEngine);
-        context.register(PPLServiceConfig.class);
-        context.refresh();
-        pplService = context.getBean(PPLService.class);
-    }
-
-    @Test
-    public void testExecuteShouldPass() {
-        doAnswer(invocation -> {
-            ResponseListener<QueryResponse> listener = invocation.getArgument(1);
-            listener.onResponse(new QueryResponse(Collections.emptyList()));
-            return null;
-        }).when(executionEngine).execute(any(), any());
-
-        pplService.execute(new PPLQueryRequest("search source=t a=1", null), new ResponseListener<QueryResponse>() {
-            @Override
-            public void onResponse(QueryResponse pplQueryResponse) {
-
-            }
-
-            @Override
-            public void onFailure(Exception e) {
-                Assert.fail();
-            }
-        });
-    }
-
-    @Test
-    public void testExecuteWithIllegalQueryShouldBeCaughtByHandler() {
-        pplService.execute(new PPLQueryRequest("search", null), new ResponseListener<QueryResponse>() {
-            @Override
-            public void onResponse(QueryResponse pplQueryResponse) {
-                Assert.fail();
-            }
-
-            @Override
-            public void onFailure(Exception e) {
-
-            }
+  private AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
+
+  private PPLService pplService;
+
+  @Mock
+  private StorageEngine storageEngine;
+
+  @Mock
+  private ExecutionEngine executionEngine;
+
+  @Mock
+  private Table table;
+
+  @Mock
+  private PhysicalPlan plan;
+
+  /**
+   * Setup the test context.
+   */
+  @Before
+  public void setUp() {
+    when(table.getFieldTypes()).thenReturn(ImmutableMap.of("a", ExprType.INTEGER));
+    when(table.implement(any())).thenReturn(plan);
+    when(storageEngine.getTable(any())).thenReturn(table);
+
+    context.registerBean(StorageEngine.class, () -> storageEngine);
+    context.registerBean(ExecutionEngine.class, () -> executionEngine);
+    context.register(PPLServiceConfig.class);
+    context.refresh();
+    pplService = context.getBean(PPLService.class);
+  }
+
+  @Test
+  public void testExecuteShouldPass() {
+    doAnswer(invocation -> {
+      ResponseListener<QueryResponse> listener = invocation.getArgument(1);
+      listener.onResponse(new QueryResponse(Collections.emptyList()));
+      return null;
+    }).when(executionEngine).execute(any(), any());
+
+    pplService.execute(new PPLQueryRequest("search source=t a=1", null),
+        new ResponseListener<QueryResponse>() {
+          @Override
+          public void onResponse(QueryResponse pplQueryResponse) {
+
+          }
+
+          @Override
+          public void onFailure(Exception e) {
+            Assert.fail();
+          }
         });
-    }
+  }
+
+  @Test
+  public void testExecuteWithIllegalQueryShouldBeCaughtByHandler() {
+    pplService.execute(new PPLQueryRequest("search", null), new ResponseListener<QueryResponse>() {
+      @Override
+      public void onResponse(QueryResponse pplQueryResponse) {
+        Assert.fail();
+      }
+
+      @Override
+      public void onFailure(Exception e) {
+
+      }
+    });
+  }
 }
\ No newline at end of file
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParserTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParserTest.java
index 9933cadddd..a847181847 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParserTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/antlr/PPLSyntaxParserTest.java
@@ -15,40 +15,40 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.antlr;
 
+import static org.junit.Assert.assertNotEquals;
+
 import org.antlr.v4.runtime.tree.ParseTree;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 
-import static org.junit.Assert.assertNotEquals;
-
 public class PPLSyntaxParserTest {
-    @Rule
-    public ExpectedException exceptionRule = ExpectedException.none();
-
-    @Test
-    public void testSearchCommandShouldPass() {
-        ParseTree tree = new PPLSyntaxParser().analyzeSyntax("search source=t a=1 b=2");
-        assertNotEquals(null, tree);
-    }
-
-    @Test
-    public void testSearchCommandIgnoreSearchKeywordShouldPass() {
-        ParseTree tree = new PPLSyntaxParser().analyzeSyntax("source=t a=1 b=2");
-        assertNotEquals(null, tree);
-    }
-
-    @Test
-    public void testSearchFieldsCommandShouldPass() {
-        ParseTree tree = new PPLSyntaxParser().analyzeSyntax("search source=t a=1 b=2 | fields a,b");
-        assertNotEquals(null, tree);
-    }
-
-    @Test
-    public void testSearchCommandWithoutSourceShouldFail() {
-        exceptionRule.expect(RuntimeException.class);
-        exceptionRule.expectMessage("Failed to parse query due to offending symbol");
-
-        new PPLSyntaxParser().analyzeSyntax("search a=1");
-    }
+  @Rule
+  public ExpectedException exceptionRule = ExpectedException.none();
+
+  @Test
+  public void testSearchCommandShouldPass() {
+    ParseTree tree = new PPLSyntaxParser().analyzeSyntax("search source=t a=1 b=2");
+    assertNotEquals(null, tree);
+  }
+
+  @Test
+  public void testSearchCommandIgnoreSearchKeywordShouldPass() {
+    ParseTree tree = new PPLSyntaxParser().analyzeSyntax("source=t a=1 b=2");
+    assertNotEquals(null, tree);
+  }
+
+  @Test
+  public void testSearchFieldsCommandShouldPass() {
+    ParseTree tree = new PPLSyntaxParser().analyzeSyntax("search source=t a=1 b=2 | fields a,b");
+    assertNotEquals(null, tree);
+  }
+
+  @Test
+  public void testSearchCommandWithoutSourceShouldFail() {
+    exceptionRule.expect(RuntimeException.class);
+    exceptionRule.expectMessage("Failed to parse query due to offending symbol");
+
+    new PPLSyntaxParser().analyzeSyntax("search a=1");
+  }
 }
\ No newline at end of file
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfigTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfigTest.java
index c802e20348..15a8d9f537 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfigTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/config/PPLServiceConfigTest.java
@@ -15,15 +15,16 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.config;
 
+import static org.junit.Assert.assertNotNull;
+
 import com.amazon.opendistroforelasticsearch.sql.ppl.PPLService;
 import org.junit.Test;
-import static org.junit.Assert.assertNotNull;
 
 public class PPLServiceConfigTest {
-    @Test
-    public void testConfigPPLServiceShouldPass() {
-        PPLServiceConfig config = new PPLServiceConfig();
-        PPLService service = config.pplService();
-        assertNotNull(service);
-    }
+  @Test
+  public void testConfigPPLServiceShouldPass() {
+    PPLServiceConfig config = new PPLServiceConfig();
+    PPLService service = config.pplService();
+    assertNotNull(service);
+  }
 }
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequestTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequestTest.java
index 70dbf00a0b..0b1e959d22 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequestTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryRequestTest.java
@@ -18,9 +18,9 @@
 import org.junit.Test;
 
 public class PPLQueryRequestTest {
-    @Test
-    public void getRequestShouldPass() {
-        PPLQueryRequest request = new PPLQueryRequest("source=t a=1", null);
-        request.getRequest();
-    }
+  @Test
+  public void getRequestShouldPass() {
+    PPLQueryRequest request = new PPLQueryRequest("source=t a=1", null);
+    request.getRequest();
+  }
 }
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryResponseTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryResponseTest.java
index df2afc2111..4a721d1aff 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryResponseTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/domain/PPLQueryResponseTest.java
@@ -18,8 +18,8 @@
 import org.junit.Test;
 
 public class PPLQueryResponseTest {
-    @Test
-    public void testQueryResponse() {
-        PPLQueryResponse response = new PPLQueryResponse();
-    }
+  @Test
+  public void testQueryResponse() {
+    PPLQueryResponse response = new PPLQueryResponse();
+  }
 }
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilderTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilderTest.java
index bdbe772f17..4ed1409311 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilderTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstBuilderTest.java
@@ -15,12 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.parser;
 
-import com.amazon.opendistroforelasticsearch.sql.ppl.antlr.PPLSyntaxParser;
-import com.amazon.opendistroforelasticsearch.sql.ast.Node;
-import java.util.Collections;
-import org.junit.Ignore;
-import org.junit.Test;
-
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.agg;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.aggregate;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.argument;
@@ -29,8 +23,8 @@
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.dedupe;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultDedupArgs;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultFieldsArgs;
-import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortOptions;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortFieldArgs;
+import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortOptions;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultStatsArgs;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.eval;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.exprList;
@@ -41,7 +35,6 @@
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.let;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.map;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.nullLiteral;
-import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.project;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.projectWithArg;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.relation;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.rename;
@@ -51,223 +44,230 @@
 import static java.util.Collections.emptyList;
 import static org.junit.Assert.assertEquals;
 
-public class AstBuilderTest {
+import com.amazon.opendistroforelasticsearch.sql.ast.Node;
+import com.amazon.opendistroforelasticsearch.sql.ppl.antlr.PPLSyntaxParser;
+import org.junit.Ignore;
+import org.junit.Test;
 
-    @Test
-    public void testSearchCommand() {
-        assertEqual("search source=t a=1",
-                filter(
-                        relation("t"),
-                        compare("=", field("a"), intLiteral(1))
-                )
-        );
-    }
+public class AstBuilderTest {
 
-    @Test
-    public void testSearchCommandString() {
-        assertEqual("search source=t a=\"a\"",
-                filter(
-                        relation("t"),
-                        compare("=", field("a"), stringLiteral("a"))
-                )
-        );
-    }
+  private PPLSyntaxParser parser = new PPLSyntaxParser();
+  private AstBuilder astBuilder = new AstBuilder(new AstExpressionBuilder());
 
-    @Test
-    public void testSearchCommandWithoutSearch() {
-        assertEqual("source=t a=1",
-                filter(
-                        relation("t"),
-                        compare("=", field("a"), intLiteral(1))
-                )
-        );
-    }
+  @Test
+  public void testSearchCommand() {
+    assertEqual("search source=t a=1",
+        filter(
+            relation("t"),
+            compare("=", field("a"), intLiteral(1))
+        )
+    );
+  }
 
-    @Test
-    public void testSearchCommandWithFilterBeforeSource() {
-        assertEqual("search a=1 source=t",
-                filter(
-                        relation("t"),
-                        compare("=", field("a"), intLiteral(1))
-                ));
-    }
+  @Test
+  public void testSearchCommandString() {
+    assertEqual("search source=t a=\"a\"",
+        filter(
+            relation("t"),
+            compare("=", field("a"), stringLiteral("a"))
+        )
+    );
+  }
 
-    @Test
-    public void testWhereCommand() {
-        assertEqual("search source=t | where a=1",
-                filter(
-                        relation("t"),
-                        compare("=", field("a"), intLiteral(1))
-                )
-        );
-    }
+  @Test
+  public void testSearchCommandWithoutSearch() {
+    assertEqual("source=t a=1",
+        filter(
+            relation("t"),
+            compare("=", field("a"), intLiteral(1))
+        )
+    );
+  }
 
-    @Test
-    public void testFieldsCommandWithoutArguments() {
-        assertEqual("source=t | fields f, g",
-                projectWithArg(
-                        relation("t"),
-                        defaultFieldsArgs(),
-                        field("f"), field("g")
-                ));
-    }
+  @Test
+  public void testSearchCommandWithFilterBeforeSource() {
+    assertEqual("search a=1 source=t",
+        filter(
+            relation("t"),
+            compare("=", field("a"), intLiteral(1))
+        ));
+  }
 
-    @Test
-    public void testFieldsCommandWithIncludeArguments() {
-        assertEqual("source=t | fields + f, g",
-                projectWithArg(
-                        relation("t"),
-                        defaultFieldsArgs(),
-                        field("f"), field("g")
-                ));
-    }
+  @Test
+  public void testWhereCommand() {
+    assertEqual("search source=t | where a=1",
+        filter(
+            relation("t"),
+            compare("=", field("a"), intLiteral(1))
+        )
+    );
+  }
 
-    @Test
-    public void testFieldsCommandWithExcludeArguments() {
-        assertEqual("source=t | fields - f, g",
-                projectWithArg(
-                        relation("t"),
-                        exprList(argument("exclude", booleanLiteral(true))),
-                        field("f"), field("g")
-                ));
-    }
+  @Test
+  public void testFieldsCommandWithoutArguments() {
+    assertEqual("source=t | fields f, g",
+        projectWithArg(
+            relation("t"),
+            defaultFieldsArgs(),
+            field("f"), field("g")
+        ));
+  }
 
-    @Test
-    public void testRenameCommand() {
-        assertEqual("source=t | rename f as g",
-                rename(
-                        relation("t"),
-                        map("f", "g")
-                ));
-    }
+  @Test
+  public void testFieldsCommandWithIncludeArguments() {
+    assertEqual("source=t | fields + f, g",
+        projectWithArg(
+            relation("t"),
+            defaultFieldsArgs(),
+            field("f"), field("g")
+        ));
+  }
 
-    @Test
-    public void testStatsCommand() {
-        assertEqual("source=t | stats count(a)",
-                agg(
-                        relation("t"),
-                        exprList(
-                                aggregate("count", field("a"))
-                        ),
-                        emptyList(),
-                        emptyList(),
-                        defaultStatsArgs()
-                ));
-    }
+  @Test
+  public void testFieldsCommandWithExcludeArguments() {
+    assertEqual("source=t | fields - f, g",
+        projectWithArg(
+            relation("t"),
+            exprList(argument("exclude", booleanLiteral(true))),
+            field("f"), field("g")
+        ));
+  }
 
-    @Test
-    public void testStatsCommandWithByClause() {
-        assertEqual("source=t | stats count(a) by b DEDUP_SPLITVALUES=false",
-                agg(
-                        relation("t"),
-                        exprList(
-                                aggregate("count", field("a"))
-                        ),
-                        emptyList(),
-                        exprList(field("b")),
-                        defaultStatsArgs()
-                ));
-    }
+  @Test
+  public void testRenameCommand() {
+    assertEqual("source=t | rename f as g",
+        rename(
+            relation("t"),
+            map("f", "g")
+        ));
+  }
 
+  @Test
+  public void testStatsCommand() {
+    assertEqual("source=t | stats count(a)",
+        agg(
+            relation("t"),
+            exprList(
+                aggregate("count", field("a"))
+            ),
+            emptyList(),
+            emptyList(),
+            defaultStatsArgs()
+        ));
+  }
 
-    @Test
-    public void testStatsCommandWithAlias() {
-        assertEqual("source=t | stats count(a) as alias",
-                rename(
-                        agg(
-                                relation("t"),
-                                exprList(
-                                    aggregate("count", field("a"))
-                                ),
-                                emptyList(),
-                                emptyList(),
-                                defaultStatsArgs()
-                        ),
-                        map(aggregate("count", field("a")), field("alias"))
-                )
-        );
-    }
+  @Test
+  public void testStatsCommandWithByClause() {
+    assertEqual("source=t | stats count(a) by b DEDUP_SPLITVALUES=false",
+        agg(
+            relation("t"),
+            exprList(
+                aggregate("count", field("a"))
+            ),
+            emptyList(),
+            exprList(field("b")),
+            defaultStatsArgs()
+        ));
+  }
 
-    @Test
-    public void testDedupCommand() {
-        assertEqual("source=t | dedup f1, f2",
-                dedupe(
-                        relation("t"),
-                        defaultDedupArgs(),
-                        field("f1"), field("f2")
-                ));
-    }
+  @Test
+  public void testStatsCommandWithAlias() {
+    assertEqual("source=t | stats count(a) as alias",
+        rename(
+            agg(
+                relation("t"),
+                exprList(
+                    aggregate("count", field("a"))
+                ),
+                emptyList(),
+                emptyList(),
+                defaultStatsArgs()
+            ),
+            map(aggregate("count", field("a")), field("alias"))
+        )
+    );
+  }
 
-    @Ignore(value = "disable sortby from the dedup command syntax")
-    public void testDedupCommandWithSortby() {
-        assertEqual("source=t | dedup f1, f2 sortby f3",
-                agg(
-                        relation("t"),
-                        exprList(field("f1"), field("f2")),
-                        exprList(field("f3", defaultSortFieldArgs())),
-                        null,
-                        defaultDedupArgs()
-                ));
-    }
+  @Test
+  public void testDedupCommand() {
+    assertEqual("source=t | dedup f1, f2",
+        dedupe(
+            relation("t"),
+            defaultDedupArgs(),
+            field("f1"), field("f2")
+        ));
+  }
 
-    @Test
-    public void testSortCommand() {
-        assertEqual("source=t | sort f1, f2",
-                sort(
-                    relation("t"),
-                    defaultSortOptions(),
-                    field("f1", defaultSortFieldArgs()),
-                    field("f2", defaultSortFieldArgs())
-                ));
-    }
+  /**
+   * disable sortby from the dedup command syntax.
+   */
+  @Ignore(value = "disable sortby from the dedup command syntax")
+  public void testDedupCommandWithSortby() {
+    assertEqual("source=t | dedup f1, f2 sortby f3",
+        agg(
+            relation("t"),
+            exprList(field("f1"), field("f2")),
+            exprList(field("f3", defaultSortFieldArgs())),
+            null,
+            defaultDedupArgs()
+        ));
+  }
 
-    @Test
-    public void testSortCommandWithOptions() {
-      assertEqual("source=t | sort 100 - f1, + f2",
-          sort(
-              relation("t"),
-              sortOptions(100),
-              field("f1", exprList(argument("asc", booleanLiteral(false)),
-                  argument("type", nullLiteral()))),
-              field("f2", defaultSortFieldArgs())
-          ));
-    }
+  @Test
+  public void testSortCommand() {
+    assertEqual("source=t | sort f1, f2",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field("f1", defaultSortFieldArgs()),
+            field("f2", defaultSortFieldArgs())
+        ));
+  }
 
-    @Test
-    public void testEvalCommand() {
-        assertEqual("source=t | eval r=abs(f)",
-                eval(
-                        relation("t"),
-                        let(
-                                field("r"),
-                                function("abs", field("f"))
-                        )
-                ));
-    }
+  @Test
+  public void testSortCommandWithOptions() {
+    assertEqual("source=t | sort 100 - f1, + f2",
+        sort(
+            relation("t"),
+            sortOptions(100),
+            field("f1", exprList(argument("asc", booleanLiteral(false)),
+                argument("type", nullLiteral()))),
+            field("f2", defaultSortFieldArgs())
+        ));
+  }
 
-    @Test
-    public void testIndexName() {
-        assertEqual("source=`log.2020.04.20.` a=1",
-                filter(
-                        relation("log.2020.04.20."),
-                        compare("=", field("a"), intLiteral(1))
-                ));
-    }
+  @Test
+  public void testEvalCommand() {
+    assertEqual("source=t | eval r=abs(f)",
+        eval(
+            relation("t"),
+            let(
+                field("r"),
+                function("abs", field("f"))
+            )
+        ));
+  }
 
-    protected void assertEqual(String query, Node expectedPlan) {
-        Node actualPlan = plan(query);
-        assertEquals(expectedPlan, actualPlan);
-    }
+  @Test
+  public void testIndexName() {
+    assertEqual("source=`log.2020.04.20.` a=1",
+        filter(
+            relation("log.2020.04.20."),
+            compare("=", field("a"), intLiteral(1))
+        ));
+  }
 
-    protected void assertEqual(String query, String expected) {
-        Node expectedPlan = plan(expected);
-        assertEqual(query, expectedPlan);
-    }
+  protected void assertEqual(String query, Node expectedPlan) {
+    Node actualPlan = plan(query);
+    assertEquals(expectedPlan, actualPlan);
+  }
 
-    private PPLSyntaxParser parser = new PPLSyntaxParser();
-    private AstBuilder astBuilder = new AstBuilder(new AstExpressionBuilder());
+  protected void assertEqual(String query, String expected) {
+    Node expectedPlan = plan(expected);
+    assertEqual(query, expectedPlan);
+  }
 
-    private Node plan(String query) {
-        return astBuilder.visit(parser.analyzeSyntax(query));
-    }
+  private Node plan(String query) {
+    return astBuilder.visit(parser.analyzeSyntax(query));
+  }
 }
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilderTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilderTest.java
index 2a8cdeb2ac..4d0e2432f1 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilderTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/parser/AstExpressionBuilderTest.java
@@ -15,8 +15,6 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.parser;
 
-import org.junit.Ignore;
-import org.junit.Test;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.agg;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.aggregate;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.and;
@@ -24,8 +22,8 @@
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.booleanLiteral;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.compare;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultFieldsArgs;
-import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortOptions;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortFieldArgs;
+import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortOptions;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultStatsArgs;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.doubleLiteral;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.equalTo;
@@ -47,331 +45,337 @@
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.stringLiteral;
 import static java.util.Collections.emptyList;
 
-public class AstExpressionBuilderTest extends AstBuilderTest{
-
-    @Test
-    public void testLogicalNotExpr() {
-        assertEqual("source=t not a=1",
-                filter(
-                        relation("t"),
-                        not(
-                                compare("=", field("a"), intLiteral(1))
-                        )
-                ));
-    }
-
-    @Test
-    public void testLogicalOrExpr() {
-        assertEqual("source=t a=1 or b=2",
-                filter(
-                        relation("t"),
-                        or(
-                                compare("=", field("a"), intLiteral(1)),
-                                compare("=", field("b"), intLiteral(2))
-                        )
-                ));
-    }
-
-    @Test
-    public void testLogicalAndExpr() {
-        assertEqual("source=t a=1 and b=2",
-                filter(
-                        relation("t"),
-                        and(
-                                compare("=", field("a"), intLiteral(1)),
-                                compare("=", field("b"), intLiteral(2))
-                        )
-                ));
-    }
-
-    @Test
-    public void testLogicalAndExprWithoutKeywordAnd() {
-        assertEqual("source=t a=1 b=2",
-                filter(
-                        relation("t"),
-                        and(
-                                compare("=", field("a"), intLiteral(1)),
-                                compare("=", field("b"), intLiteral(2))
-                        )
-                ));
-    }
-
-    @Ignore("search operator should not include functionCall, need to change antlr")
-    public void testEvalExpr() {
-        assertEqual("source=t f=abs(a)",
-                filter(
-                        relation("t"),
-                        equalTo(
-                                field("f"),
-                                function("abs", field("a"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testEvalFunctionExpr() {
-        assertEqual("source=t | eval f=abs(a)",
-                eval(
-                        relation("t"),
-                        let(
-                                field("f"),
-                                function("abs", field("a"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testEvalBinaryOperationExpr() {
-        assertEqual("source=t | eval f=a+b",
-                eval(
-                        relation("t"),
-                        let(
-                                field("f"),
-                                function("+", field("a"), field("b"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testLiteralValueBinaryOperationExpr() {
-        assertEqual("source=t | eval f=3+2",
-                eval(
-                        relation("t"),
-                        let(
-                                field("f"),
-                                function("+", intLiteral(3), intLiteral(2))
-                        )
-                ));
-    }
-
-    @Test
-    public void testCompareExpr() {
-        assertEqual("source=t a='b'",
-                filter(
-                        relation("t"),
-                        compare("=", field("a"), stringLiteral("b"))
-                ));
-    }
-
-    @Test
-    public void testCompareFieldsExpr() {
-        assertEqual("source=t a>b",
-                filter(
-                        relation("t"),
-                        compare(">", field("a"), field("b"))
-                ));
-    }
-
-    @Test
-    public void testInExpr() {
-        assertEqual("source=t f in (1, 2, 3)",
-                filter(
-                        relation("t"),
-                        in(
-                                field("f"),
-                                intLiteral(1), intLiteral(2), intLiteral(3))
-                ));
-    }
-
-    @Test
-    public void testFieldExpr() {
-        assertEqual("source=t | sort + f",
-                sort(
-                        relation("t"),
-                        defaultSortOptions(),
-                        field("f", defaultSortFieldArgs())
-                ));
-    }
-
-    @Test
-    public void testSortFieldWithMinusKeyword() {
-        assertEqual("source=t | sort - f",
-                sort(
-                        relation("t"),
-                        defaultSortOptions(),
-                        field(
-                            "f",
-                            argument("asc", booleanLiteral(false)),
-                            argument("type", nullLiteral())
-                        )
-                ));
-    }
-
-    @Test
-    public void testSortFieldWithAutoKeyword() {
-        assertEqual("source=t | sort auto(f)",
-                sort(
-                        relation("t"),
-                        defaultSortOptions(),
-                        field(
-                                "f",
-                                argument("asc", booleanLiteral(true)),
-                                argument("type", stringLiteral("auto"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testSortFieldWithIpKeyword() {
-        assertEqual("source=t | sort ip(f)",
-              sort(
-                        relation("t"),
-                        defaultSortOptions(),
-                        field(
-                                "f",
-                                argument("asc", booleanLiteral(true)),
-                                argument("type", stringLiteral("ip"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testSortFieldWithNumKeyword() {
-        assertEqual("source=t | sort num(f)",
-                sort(
-                        relation("t"),
-                        defaultSortOptions(),
-                        field(
-                            "f",
-                            argument("asc", booleanLiteral(true)),
-                            argument("type", stringLiteral("num"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testSortFieldWithStrKeyword() {
-        assertEqual("source=t | sort str(f)",
-                sort(
-                      relation("t"),
-                      defaultSortOptions(),
-                      field(
-                          "f",
-                          argument("asc", booleanLiteral(true)),
-                          argument("type", stringLiteral("str"))
-                      )
-                ));
-    }
-
-    @Test
-    public void testAggFuncCallExpr() {
-        assertEqual("source=t | stats avg(a) by b",
-                agg(
-                        relation("t"),
-                        exprList(
-                                aggregate("avg", field("a"))
-
-                        ),
-                        emptyList(),
-                        exprList(field("b")),
-                        defaultStatsArgs()
-                ));
-    }
-
-    @Test
-    public void testPercentileAggFuncExpr() {
-        assertEqual("source=t | stats percentile<1>(a)",
-                agg(
-                        relation("t"),
-                        exprList(
-                                aggregate(
-                                        "percentile",
-                                        field("a"),
-                                        argument("rank", intLiteral(1))
-                                )
-                        ),
-                        emptyList(),
-                        emptyList(),
-                        defaultStatsArgs()
-                ));
-    }
-
-    @Test
-    public void testEvalFuncCallExpr() {
-        assertEqual("source=t | eval f=abs(a)",
-                eval(
-                        relation("t"),
-                        let(
-                                field("f"),
-                                function("abs", field("a"))
-                        )
-                ));
-    }
-
-    @Test
-    public void testNestedFieldName() {
-        assertEqual("source=t | fields field0.field1.field2",
-                projectWithArg(
-                        relation("t"),
-                        defaultFieldsArgs(),
-                        field(
-                                qualifiedName("field0", "field1", "field2")
-                        )
-                ));
-    }
-
-    @Test
-    public void testFieldNameWithSpecialChars() {
-        assertEqual("source=t | fields `field-0`.`field#1`.`field*2`",
-                projectWithArg(
-                        relation("t"),
-                        defaultFieldsArgs(),
-                        field(
-                                qualifiedName("field-0", "field#1", "field*2")
-                        )
-                ));
-    }
-
-    @Test
-    public void testStringLiteralExpr() {
-        assertEqual("source=t a=\"string\"",
-                filter(
-                        relation("t"),
-                        compare(
-                                "=",
-                                field("a"),
-                                stringLiteral("string")
-                        )
-                ));
-    }
-
-    @Test
-    public void testIntegerLiteralExpr() {
-        assertEqual("source=t a=1",
-                filter(
-                        relation("t"),
-                        compare(
-                                "=",
-                                field("a"),
-                                intLiteral(1)
-                        )
-                ));
-    }
-
-    @Test
-    public void testDoubleLiteralExpr() {
-        assertEqual("source=t b=0.1",
-                filter(
-                        relation("t"),
-                        compare(
-                                "=",
-                                field("b"),
-                                doubleLiteral(0.1)
-                        )
-                ));
-    }
-
-    @Test
-    public void testBooleanLiteralExpr() {
-        assertEqual("source=t a=true",
-                filter(
-                        relation("t"),
-                        compare(
-                                "=",
-                                field("a"),
-                                booleanLiteral(true)
-                        )
-                ));
-    }
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class AstExpressionBuilderTest extends AstBuilderTest {
+
+  @Test
+  public void testLogicalNotExpr() {
+    assertEqual("source=t not a=1",
+        filter(
+            relation("t"),
+            not(
+                compare("=", field("a"), intLiteral(1))
+            )
+        ));
+  }
+
+  @Test
+  public void testLogicalOrExpr() {
+    assertEqual("source=t a=1 or b=2",
+        filter(
+            relation("t"),
+            or(
+                compare("=", field("a"), intLiteral(1)),
+                compare("=", field("b"), intLiteral(2))
+            )
+        ));
+  }
+
+  @Test
+  public void testLogicalAndExpr() {
+    assertEqual("source=t a=1 and b=2",
+        filter(
+            relation("t"),
+            and(
+                compare("=", field("a"), intLiteral(1)),
+                compare("=", field("b"), intLiteral(2))
+            )
+        ));
+  }
+
+  @Test
+  public void testLogicalAndExprWithoutKeywordAnd() {
+    assertEqual("source=t a=1 b=2",
+        filter(
+            relation("t"),
+            and(
+                compare("=", field("a"), intLiteral(1)),
+                compare("=", field("b"), intLiteral(2))
+            )
+        ));
+  }
+
+  /**
+   * Todo. search operator should not include functionCall, need to change antlr.
+   */
+  @Ignore("search operator should not include functionCall, need to change antlr")
+  public void testEvalExpr() {
+    assertEqual("source=t f=abs(a)",
+        filter(
+            relation("t"),
+            equalTo(
+                field("f"),
+                function("abs", field("a"))
+            )
+        ));
+  }
+
+  @Test
+  public void testEvalFunctionExpr() {
+    assertEqual("source=t | eval f=abs(a)",
+        eval(
+            relation("t"),
+            let(
+                field("f"),
+                function("abs", field("a"))
+            )
+        ));
+  }
+
+  @Test
+  public void testEvalBinaryOperationExpr() {
+    assertEqual("source=t | eval f=a+b",
+        eval(
+            relation("t"),
+            let(
+                field("f"),
+                function("+", field("a"), field("b"))
+            )
+        ));
+  }
+
+  @Test
+  public void testLiteralValueBinaryOperationExpr() {
+    assertEqual("source=t | eval f=3+2",
+        eval(
+            relation("t"),
+            let(
+                field("f"),
+                function("+", intLiteral(3), intLiteral(2))
+            )
+        ));
+  }
+
+  @Test
+  public void testCompareExpr() {
+    assertEqual("source=t a='b'",
+        filter(
+            relation("t"),
+            compare("=", field("a"), stringLiteral("b"))
+        ));
+  }
+
+  @Test
+  public void testCompareFieldsExpr() {
+    assertEqual("source=t a>b",
+        filter(
+            relation("t"),
+            compare(">", field("a"), field("b"))
+        ));
+  }
+
+  @Test
+  public void testInExpr() {
+    assertEqual("source=t f in (1, 2, 3)",
+        filter(
+            relation("t"),
+            in(
+                field("f"),
+                intLiteral(1), intLiteral(2), intLiteral(3))
+        ));
+  }
+
+  @Test
+  public void testFieldExpr() {
+    assertEqual("source=t | sort + f",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field("f", defaultSortFieldArgs())
+        ));
+  }
+
+  @Test
+  public void testSortFieldWithMinusKeyword() {
+    assertEqual("source=t | sort - f",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field(
+                "f",
+                argument("asc", booleanLiteral(false)),
+                argument("type", nullLiteral())
+            )
+        ));
+  }
+
+  @Test
+  public void testSortFieldWithAutoKeyword() {
+    assertEqual("source=t | sort auto(f)",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field(
+                "f",
+                argument("asc", booleanLiteral(true)),
+                argument("type", stringLiteral("auto"))
+            )
+        ));
+  }
+
+  @Test
+  public void testSortFieldWithIpKeyword() {
+    assertEqual("source=t | sort ip(f)",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field(
+                "f",
+                argument("asc", booleanLiteral(true)),
+                argument("type", stringLiteral("ip"))
+            )
+        ));
+  }
+
+  @Test
+  public void testSortFieldWithNumKeyword() {
+    assertEqual("source=t | sort num(f)",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field(
+                "f",
+                argument("asc", booleanLiteral(true)),
+                argument("type", stringLiteral("num"))
+            )
+        ));
+  }
+
+  @Test
+  public void testSortFieldWithStrKeyword() {
+    assertEqual("source=t | sort str(f)",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field(
+                "f",
+                argument("asc", booleanLiteral(true)),
+                argument("type", stringLiteral("str"))
+            )
+        ));
+  }
+
+  @Test
+  public void testAggFuncCallExpr() {
+    assertEqual("source=t | stats avg(a) by b",
+        agg(
+            relation("t"),
+            exprList(
+                aggregate("avg", field("a"))
+
+            ),
+            emptyList(),
+            exprList(field("b")),
+            defaultStatsArgs()
+        ));
+  }
+
+  @Test
+  public void testPercentileAggFuncExpr() {
+    assertEqual("source=t | stats percentile<1>(a)",
+        agg(
+            relation("t"),
+            exprList(
+                aggregate(
+                    "percentile",
+                    field("a"),
+                    argument("rank", intLiteral(1))
+                )
+            ),
+            emptyList(),
+            emptyList(),
+            defaultStatsArgs()
+        ));
+  }
+
+  @Test
+  public void testEvalFuncCallExpr() {
+    assertEqual("source=t | eval f=abs(a)",
+        eval(
+            relation("t"),
+            let(
+                field("f"),
+                function("abs", field("a"))
+            )
+        ));
+  }
+
+  @Test
+  public void testNestedFieldName() {
+    assertEqual("source=t | fields field0.field1.field2",
+        projectWithArg(
+            relation("t"),
+            defaultFieldsArgs(),
+            field(
+                qualifiedName("field0", "field1", "field2")
+            )
+        ));
+  }
+
+  @Test
+  public void testFieldNameWithSpecialChars() {
+    assertEqual("source=t | fields `field-0`.`field#1`.`field*2`",
+        projectWithArg(
+            relation("t"),
+            defaultFieldsArgs(),
+            field(
+                qualifiedName("field-0", "field#1", "field*2")
+            )
+        ));
+  }
+
+  @Test
+  public void testStringLiteralExpr() {
+    assertEqual("source=t a=\"string\"",
+        filter(
+            relation("t"),
+            compare(
+                "=",
+                field("a"),
+                stringLiteral("string")
+            )
+        ));
+  }
+
+  @Test
+  public void testIntegerLiteralExpr() {
+    assertEqual("source=t a=1",
+        filter(
+            relation("t"),
+            compare(
+                "=",
+                field("a"),
+                intLiteral(1)
+            )
+        ));
+  }
+
+  @Test
+  public void testDoubleLiteralExpr() {
+    assertEqual("source=t b=0.1",
+        filter(
+            relation("t"),
+            compare(
+                "=",
+                field("b"),
+                doubleLiteral(0.1)
+            )
+        ));
+  }
+
+  @Test
+  public void testBooleanLiteralExpr() {
+    assertEqual("source=t a=true",
+        filter(
+            relation("t"),
+            compare(
+                "=",
+                field("a"),
+                booleanLiteral(true)
+            )
+        ));
+  }
 
 }
diff --git a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactoryTest.java b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactoryTest.java
index 85caaee74d..f2400b5ade 100644
--- a/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactoryTest.java
+++ b/ppl/src/test/java/com/amazon/opendistroforelasticsearch/sql/ppl/utils/ArgumentFactoryTest.java
@@ -15,15 +15,13 @@
 
 package com.amazon.opendistroforelasticsearch.sql.ppl.utils;
 
-import com.amazon.opendistroforelasticsearch.sql.ppl.parser.AstBuilderTest;
-import org.junit.Test;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.agg;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.aggregate;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.argument;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.booleanLiteral;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.dedupe;
-import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortOptions;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortFieldArgs;
+import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.defaultSortOptions;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.exprList;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.field;
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.intLiteral;
@@ -33,110 +31,114 @@
 import static com.amazon.opendistroforelasticsearch.sql.ast.dsl.AstDSL.stringLiteral;
 import static java.util.Collections.emptyList;
 
+import com.amazon.opendistroforelasticsearch.sql.ppl.parser.AstBuilderTest;
+import org.junit.Test;
+
 public class ArgumentFactoryTest extends AstBuilderTest {
 
-    @Test
-    public void testFieldsCommandArgument() {
-        assertEqual("source=t | fields - a",
-                projectWithArg(
-                        relation("t"),
-                        exprList(argument("exclude", booleanLiteral(true))),
-                        field("a")
-                ));
-    }
+  @Test
+  public void testFieldsCommandArgument() {
+    assertEqual("source=t | fields - a",
+        projectWithArg(
+            relation("t"),
+            exprList(argument("exclude", booleanLiteral(true))),
+            field("a")
+        ));
+  }
 
-    @Test
-    public void testFieldsCommandDefaultArgument() {
-        assertEqual("source=t | fields + a", "source=t | fields a");
-    }
+  @Test
+  public void testFieldsCommandDefaultArgument() {
+    assertEqual("source=t | fields + a", "source=t | fields a");
+  }
 
-    @Test
-    public void testStatsCommandArgument() {
-        assertEqual("source=t | stats partitions=1 allnum=false delim=',' avg(a) dedup_splitvalues=true",
-                agg(
-                        relation("t"),
-                        exprList(aggregate("avg", field("a"))),
-                        emptyList(),
-                        emptyList(),
-                        exprList(
-                                argument("partitions", intLiteral(1)),
-                                argument("allnum", booleanLiteral(false)),
-                                argument("delim", stringLiteral(",")),
-                                argument("dedupsplit", booleanLiteral(true))
-                        )
-                ));
-    }
+  @Test
+  public void testStatsCommandArgument() {
+    assertEqual(
+        "source=t | stats partitions=1 allnum=false delim=',' avg(a) dedup_splitvalues=true",
+        agg(
+            relation("t"),
+            exprList(aggregate("avg", field("a"))),
+            emptyList(),
+            emptyList(),
+            exprList(
+                argument("partitions", intLiteral(1)),
+                argument("allnum", booleanLiteral(false)),
+                argument("delim", stringLiteral(",")),
+                argument("dedupsplit", booleanLiteral(true))
+            )
+        ));
+  }
 
-    @Test
-    public void testStatsCommandDefaultArgument() {
-        assertEqual(
-                "source=t | stats partitions=1 allnum=false delim=' ' avg(a) dedup_splitvalues=false",
-                "source=t | stats avg(a)");
-    }
+  @Test
+  public void testStatsCommandDefaultArgument() {
+    assertEqual(
+        "source=t | stats partitions=1 allnum=false delim=' ' avg(a) dedup_splitvalues=false",
+        "source=t | stats avg(a)");
+  }
 
-    @Test
-    public void testDedupCommandArgument() {
-        assertEqual("source=t | dedup 3 field0 keepempty=false consecutive=true",
-                dedupe(
-                        relation("t"),
-                        exprList(
-                                argument("number", intLiteral(3)),
-                                argument("keepempty", booleanLiteral(false)),
-                                argument("consecutive", booleanLiteral(true))
-                        ),
-                        field("field0")
-                ));
-    }
+  @Test
+  public void testDedupCommandArgument() {
+    assertEqual("source=t | dedup 3 field0 keepempty=false consecutive=true",
+        dedupe(
+            relation("t"),
+            exprList(
+                argument("number", intLiteral(3)),
+                argument("keepempty", booleanLiteral(false)),
+                argument("consecutive", booleanLiteral(true))
+            ),
+            field("field0")
+        ));
+  }
 
-    @Test
-    public void testDedupCommandDefaultArgument() {
-        assertEqual(
-                "source=t | dedup 1 field0 keepempty=false consecutive=false",
-                "source=t | dedup field0"
-        );
-    }
+  @Test
+  public void testDedupCommandDefaultArgument() {
+    assertEqual(
+        "source=t | dedup 1 field0 keepempty=false consecutive=false",
+        "source=t | dedup field0"
+    );
+  }
 
-    @Test
-    public void testSortCommandArgument() {
-        assertEqual("source=t | sort 3 field0 desc",
-                sort(
-                        relation("t"),
-                        exprList(
-                            argument("count", intLiteral(3)),
-                            argument("desc", booleanLiteral(true))
-                        ),
-                        field("field0", defaultSortFieldArgs())
-                ));
-        assertEqual("source=t | sort 3 field0 d", "source=t | sort 3 field0 desc");
-    }
+  @Test
+  public void testSortCommandArgument() {
+    assertEqual("source=t | sort 3 field0 desc",
+        sort(
+            relation("t"),
+            exprList(
+                argument("count", intLiteral(3)),
+                argument("desc", booleanLiteral(true))
+            ),
+            field("field0", defaultSortFieldArgs())
+        ));
+    assertEqual("source=t | sort 3 field0 d", "source=t | sort 3 field0 desc");
+  }
 
-    @Test
-    public void testSortCommandDefaultArgument() {
-        assertEqual(
-                "source=t | sort 1000 field0",
-                "source=t | sort field0"
-        );
-    }
+  @Test
+  public void testSortCommandDefaultArgument() {
+    assertEqual(
+        "source=t | sort 1000 field0",
+        "source=t | sort field0"
+    );
+  }
 
-    @Test
-    public void testSortFieldArgument() {
-        assertEqual("source=t | sort - auto(field0)",
-                sort(
-                        relation("t"),
-                        defaultSortOptions(),
-                        field(
-                                "field0",
-                                exprList(
-                                        argument("asc", booleanLiteral(false)),
-                                        argument("type", stringLiteral("auto"))
-                                )
-                        )
-                ));
-    }
+  @Test
+  public void testSortFieldArgument() {
+    assertEqual("source=t | sort - auto(field0)",
+        sort(
+            relation("t"),
+            defaultSortOptions(),
+            field(
+                "field0",
+                exprList(
+                    argument("asc", booleanLiteral(false)),
+                    argument("type", stringLiteral("auto"))
+                )
+            )
+        ));
+  }
 
-    @Test
-    public void testNoArgConstructorForArgumentFactoryShouldPass() {
-        new ArgumentFactory();
-    }
+  @Test
+  public void testNoArgConstructorForArgumentFactoryShouldPass() {
+    new ArgumentFactory();
+  }
 
 }
diff --git a/protocol/build.gradle b/protocol/build.gradle
index 34e93a8353..8a90dea360 100644
--- a/protocol/build.gradle
+++ b/protocol/build.gradle
@@ -9,8 +9,8 @@ repositories {
 }
 
 dependencies {
-    compile group: 'com.google.guava', name: 'guava', version:'23.0'
-    compile group: 'org.json', name: 'json', version:'20180813' //TODO: change to other JSON lib?
+    compile group: 'com.google.guava', name: 'guava', version: '23.0'
+    compile group: 'org.json', name: 'json', version: '20180813' //TODO: change to other JSON lib?
     compile project(':core')
 
     testImplementation('org.junit.jupiter:junit-jupiter:5.6.2')
diff --git a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java
index bcb6ca91e2..45dfd5bf88 100644
--- a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java
+++ b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResult.java
@@ -18,79 +18,82 @@
 
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValue;
 import com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils;
-import lombok.RequiredArgsConstructor;
-
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.Map;
+import lombok.RequiredArgsConstructor;
 
 /**
- * Query response that encapsulates query results and isolate {@link ExprValue} related from formatter implementation.
+ * Query response that encapsulates query results and isolate {@link ExprValue}
+ * related from formatter implementation.
  */
 @RequiredArgsConstructor
 public class QueryResult implements Iterable<Object[]> {
 
-    /**
-     * Results which are collection of expression
-     */
-    private final Collection<ExprValue> exprValues;
+  /**
+   * Results which are collection of expression.
+   */
+  private final Collection<ExprValue> exprValues;
 
 
-    /**
-     * @return  size of results
-     */
-    public int size() {
-        return exprValues.size();
-    }
-
-    /**
-     * Parse column name from results
-     * @return  mapping from column names to its expression type
-     */
-    public Map<String, String> columnNameTypes() {
-        if (exprValues.isEmpty()) {
-            return Collections.emptyMap();
-        }
+  /**
+   * size of results.
+   * @return size of results
+   */
+  public int size() {
+    return exprValues.size();
+  }
 
-        // TODO: Need other way to extract header than inferring from data implicitly
-        Map<String, ExprValue> tupleValue = getFirstTupleValue();
-        return populateColumnNameAndTypes(tupleValue);
+  /**
+   * Parse column name from results.
+   *
+   * @return mapping from column names to its expression type
+   */
+  public Map<String, String> columnNameTypes() {
+    if (exprValues.isEmpty()) {
+      return Collections.emptyMap();
     }
 
-    @Override
-    public Iterator<Object[]> iterator() {
-        // Any chance to avoid copy for json response generation?
-        return exprValues.stream().
-                          map(ExprValueUtils::getTupleValue).
-                          map(Map::values).
-                          map(this::convertExprValuesToValues).
-                          iterator();
-    }
+    // TODO: Need other way to extract header than inferring from data implicitly
+    Map<String, ExprValue> tupleValue = getFirstTupleValue();
+    return populateColumnNameAndTypes(tupleValue);
+  }
 
-    private Map<String, ExprValue> getFirstTupleValue() {
-        // Assume expression is always tuple on first level
-        //  and columns (keys) of all tuple values are exactly same
-        ExprValue firstValue = exprValues.iterator().next();
-        return ExprValueUtils.getTupleValue(firstValue);
-    }
+  @Override
+  public Iterator<Object[]> iterator() {
+    // Any chance to avoid copy for json response generation?
+    return exprValues.stream()
+        .map(ExprValueUtils::getTupleValue)
+        .map(Map::values)
+        .map(this::convertExprValuesToValues)
+        .iterator();
+  }
 
-    private Map<String, String> populateColumnNameAndTypes(Map<String, ExprValue> tupleValue) {
-        // Use linked hashmap to maintain original order in tuple expression
-        Map<String, String> colNameTypes = new LinkedHashMap<>();
-        tupleValue.forEach((name, expr) -> colNameTypes.put(name, getTypeString(expr)));
-        return colNameTypes;
-    }
+  private Map<String, ExprValue> getFirstTupleValue() {
+    // Assume expression is always tuple on first level
+    //  and columns (keys) of all tuple values are exactly same
+    ExprValue firstValue = exprValues.iterator().next();
+    return ExprValueUtils.getTupleValue(firstValue);
+  }
 
-    private Object[] convertExprValuesToValues(Collection<ExprValue> exprValues) {
-        return exprValues.stream().
-                          map(ExprValue::value).
-                          toArray(Object[]::new);
-    }
+  private Map<String, String> populateColumnNameAndTypes(Map<String, ExprValue> tupleValue) {
+    // Use linked hashmap to maintain original order in tuple expression
+    Map<String, String> colNameTypes = new LinkedHashMap<>();
+    tupleValue.forEach((name, expr) -> colNameTypes.put(name, getTypeString(expr)));
+    return colNameTypes;
+  }
 
-    private String getTypeString(ExprValue exprValue) {
-        return exprValue.type().name().toLowerCase();
-    }
+  private Object[] convertExprValuesToValues(Collection<ExprValue> exprValues) {
+    return exprValues
+        .stream()
+        .map(ExprValue::value)
+        .toArray(Object[]::new);
+  }
+
+  private String getTypeString(ExprValue exprValue) {
+    return exprValue.type().name().toLowerCase();
+  }
 
 }
diff --git a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/JsonResponseFormatter.java b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/JsonResponseFormatter.java
index 7730fd9233..7b383dd0ca 100644
--- a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/JsonResponseFormatter.java
+++ b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/JsonResponseFormatter.java
@@ -16,61 +16,63 @@
 
 package com.amazon.opendistroforelasticsearch.sql.protocol.response.format;
 
+import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
+
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import org.json.JSONObject;
 
-import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
-
 /**
  * Abstract class for all JSON formatter.
- * @param <Response>    response generic type which could be DQL or DML response
+ *
+ * @param <R> response generic type which could be DQL or DML response
  */
 @RequiredArgsConstructor
-public abstract class JsonResponseFormatter<Response> implements ResponseFormatter<Response> {
+public abstract class JsonResponseFormatter<R> implements ResponseFormatter<R> {
 
-    /**
-     * JSON format styles: pretty format or compact format without indent and space
-     */
-    public enum Style {
-        PRETTY, COMPACT
-    }
+  /**
+   * JSON format styles: pretty format or compact format without indent and space.
+   */
+  public enum Style {
+    PRETTY, COMPACT
+  }
 
-    /**
-     * JSON format style
-     */
-    private final Style style;
+  /**
+   * JSON format style.
+   */
+  private final Style style;
 
 
-    @Override
-    public String format(Response response) {
-        return jsonify(buildJsonObject(response));
-    }
+  @Override
+  public String format(R response) {
+    return jsonify(buildJsonObject(response));
+  }
 
-    @Override
-    public String format(Throwable t) {
-        JsonError error = new JsonError(t.getClass().getSimpleName(),
-                                        t.getMessage());
-        return jsonify(error);
-    }
+  @Override
+  public String format(Throwable t) {
+    JsonError error = new JsonError(t.getClass().getSimpleName(),
+        t.getMessage());
+    return jsonify(error);
+  }
 
-    /**
-     * Build JSON object to generate response json string.
-     * @param response  response
-     * @return          json object for response
-     */
-    protected abstract Object buildJsonObject(Response response);
+  /**
+   * Build JSON object to generate response json string.
+   *
+   * @param response response
+   * @return json object for response
+   */
+  protected abstract Object buildJsonObject(R response);
 
 
-    private String jsonify(Object jsonObject) {
-        JSONObject json = new JSONObject(jsonObject);
-        return (style == PRETTY) ? json.toString(2) : json.toString();
-    }
+  private String jsonify(Object jsonObject) {
+    JSONObject json = new JSONObject(jsonObject);
+    return (style == PRETTY) ? json.toString(2) : json.toString();
+  }
 
-    @RequiredArgsConstructor
-    @Getter
-    public static class JsonError {
-        private final String type;
-        private final String reason;
-    }
+  @RequiredArgsConstructor
+  @Getter
+  public static class JsonError {
+    private final String type;
+    private final String reason;
+  }
 }
diff --git a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/ResponseFormatter.java b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/ResponseFormatter.java
index 0dae00fbcf..4bee88f1c2 100644
--- a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/ResponseFormatter.java
+++ b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/ResponseFormatter.java
@@ -19,20 +19,22 @@
 /**
  * Response formatter to format response to different formats.
  */
-public interface ResponseFormatter<Response> {
+public interface ResponseFormatter<R> {
 
-    /**
-     * Format response into string in expected format.
-     * @param response  response
-     * @return          string with response content formatted
-     */
-    String format(Response response);
+  /**
+   * Format response into string in expected format.
+   *
+   * @param response response
+   * @return string with response content formatted
+   */
+  String format(R response);
 
-    /**
-     * Format an exception into string.
-     * @param t     exception occurred
-     * @return      string with exception content formatted
-     */
-    String format(Throwable t);
+  /**
+   * Format an exception into string.
+   *
+   * @param t exception occurred
+   * @return string with exception content formatted
+   */
+  String format(Throwable t);
 
 }
diff --git a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatter.java b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatter.java
index d629baffbd..3a0bad1639 100644
--- a/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatter.java
+++ b/protocol/src/main/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatter.java
@@ -17,13 +17,12 @@
 package com.amazon.opendistroforelasticsearch.sql.protocol.response.format;
 
 import com.amazon.opendistroforelasticsearch.sql.protocol.response.QueryResult;
+import java.util.List;
 import lombok.Builder;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 import lombok.Singular;
 
-import java.util.List;
-
 /**
  * JSON response format with schema header and data rows. For example,
  *
@@ -46,52 +45,52 @@
  */
 public class SimpleJsonResponseFormatter extends JsonResponseFormatter<QueryResult> {
 
-    public SimpleJsonResponseFormatter(Style style) {
-        super(style);
-    }
+  public SimpleJsonResponseFormatter(Style style) {
+    super(style);
+  }
 
-    @Override
-    public Object buildJsonObject(QueryResult response) {
-        JsonResponse.JsonResponseBuilder json = JsonResponse.builder();
+  @Override
+  public Object buildJsonObject(QueryResult response) {
+    JsonResponse.JsonResponseBuilder json = JsonResponse.builder();
 
-        json.total(response.size()).
-             size(response.size());
+    json.total(response.size())
+        .size(response.size());
 
-        response.columnNameTypes().forEach((name, type) -> json.column(new Column(name, type)));
+    response.columnNameTypes().forEach((name, type) -> json.column(new Column(name, type)));
 
-        json.datarows(fetchDataRows(response));
-        return json.build();
-    }
+    json.datarows(fetchDataRows(response));
+    return json.build();
+  }
 
-    private Object[][] fetchDataRows(QueryResult response) {
-        Object[][] rows = new Object[response.size()][];
-        int i = 0;
-        for (Object[] values : response) {
-            rows[i++] = values;
-        }
-        return rows;
+  private Object[][] fetchDataRows(QueryResult response) {
+    Object[][] rows = new Object[response.size()][];
+    int i = 0;
+    for (Object[] values : response) {
+      rows[i++] = values;
     }
+    return rows;
+  }
 
-    /**
-     * org.json requires these inner data classes be public (and static)
-     */
-    @Builder
-    @Getter
-    public static class JsonResponse {
-        @Singular("column")
-        private final List<Column> schema;
+  /**
+   * org.json requires these inner data classes be public (and static)
+   */
+  @Builder
+  @Getter
+  public static class JsonResponse {
+    @Singular("column")
+    private final List<Column> schema;
 
-        private final Object[][] datarows;
+    private final Object[][] datarows;
 
-        private long total;
-        private long size;
-    }
+    private long total;
+    private long size;
+  }
 
-    @RequiredArgsConstructor
-    @Getter
-    public static class Column {
-        private final String name;
-        private final String type;
-    }
+  @RequiredArgsConstructor
+  @Getter
+  public static class Column {
+    private final String name;
+    private final String type;
+  }
 
 }
diff --git a/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResultTest.java b/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResultTest.java
index b673506365..52cf905d9a 100644
--- a/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResultTest.java
+++ b/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/QueryResultTest.java
@@ -16,81 +16,80 @@
 
 package com.amazon.opendistroforelasticsearch.sql.protocol.response;
 
-import com.google.common.collect.ImmutableMap;
-import org.junit.jupiter.api.Disabled;
-import org.junit.jupiter.api.Test;
-
-import java.util.Arrays;
-import java.util.Collections;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.tupleValue;
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.junit.jupiter.api.Assertions.fail;
 
+import com.google.common.collect.ImmutableMap;
+import java.util.Arrays;
+import java.util.Collections;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
 class QueryResultTest {
 
-    @Test
-    void size() {
-        QueryResult response = new QueryResult(Arrays.asList(
-            tupleValue(ImmutableMap.of("name", "John", "age", 20)),
-            tupleValue(ImmutableMap.of("name", "Allen", "age", 30)),
-            tupleValue(ImmutableMap.of("name", "Smith", "age", 40))
-        ));
-        assertEquals(3, response.size());
-    }
+  @Test
+  void size() {
+    QueryResult response = new QueryResult(Arrays.asList(
+        tupleValue(ImmutableMap.of("name", "John", "age", 20)),
+        tupleValue(ImmutableMap.of("name", "Allen", "age", 30)),
+        tupleValue(ImmutableMap.of("name", "Smith", "age", 40))
+    ));
+    assertEquals(3, response.size());
+  }
 
-    @Test
-    void columnNameTypes() {
-        QueryResult response = new QueryResult(Collections.singletonList(
-            tupleValue(ImmutableMap.of("name", "John", "age", 20))
-        ));
+  @Test
+  void columnNameTypes() {
+    QueryResult response = new QueryResult(Collections.singletonList(
+        tupleValue(ImmutableMap.of("name", "John", "age", 20))
+    ));
 
-        assertEquals(
-            ImmutableMap.of("name", "string", "age", "integer"),
-            response.columnNameTypes()
-        );
-    }
+    assertEquals(
+        ImmutableMap.of("name", "string", "age", "integer"),
+        response.columnNameTypes()
+    );
+  }
 
-    @Test
-    void columnNameTypesFromEmptyExprValues() {
-        QueryResult response = new QueryResult(Collections.emptyList());
-        assertTrue(response.columnNameTypes().isEmpty());
-    }
+  @Test
+  void columnNameTypesFromEmptyExprValues() {
+    QueryResult response = new QueryResult(Collections.emptyList());
+    assertTrue(response.columnNameTypes().isEmpty());
+  }
 
-    @Disabled("Need to figure out column headers in some other way than inferring from data implicitly")
-    @Test
-    void columnNameTypesFromExprValuesWithMissing() {
-        QueryResult response = new QueryResult(Arrays.asList(
-            tupleValue(ImmutableMap.of("name", "John")),
-            tupleValue(ImmutableMap.of("name", "John", "age", 20))
-        ));
+  @Disabled("Need to figure out column headers in other way than inferring from data implicitly")
+  @Test
+  void columnNameTypesFromExprValuesWithMissing() {
+    QueryResult response = new QueryResult(Arrays.asList(
+        tupleValue(ImmutableMap.of("name", "John")),
+        tupleValue(ImmutableMap.of("name", "John", "age", 20))
+    ));
 
-        assertEquals(
-            ImmutableMap.of("name", "string", "age", "integer"),
-            response.columnNameTypes()
-        );
-    }
+    assertEquals(
+        ImmutableMap.of("name", "string", "age", "integer"),
+        response.columnNameTypes()
+    );
+  }
 
-    @Test
-    void iterate() {
-        QueryResult response = new QueryResult(Arrays.asList(
-            tupleValue(ImmutableMap.of("name", "John", "age", 20)),
-            tupleValue(ImmutableMap.of("name", "Allen", "age", 30))
-        ));
+  @Test
+  void iterate() {
+    QueryResult response = new QueryResult(Arrays.asList(
+        tupleValue(ImmutableMap.of("name", "John", "age", 20)),
+        tupleValue(ImmutableMap.of("name", "Allen", "age", 30))
+    ));
 
-        int i = 0;
-        for (Object[] objects : response) {
-            if (i == 0) {
-                assertArrayEquals(new Object[]{"John", 20}, objects);
-            } else if (i == 1) {
-                assertArrayEquals(new Object[]{"Allen", 30}, objects);
-            } else {
-                fail("More rows returned than expected");
-            }
-            i++;
-        }
+    int i = 0;
+    for (Object[] objects : response) {
+      if (i == 0) {
+        assertArrayEquals(new Object[] {"John", 20}, objects);
+      } else if (i == 1) {
+        assertArrayEquals(new Object[] {"Allen", 30}, objects);
+      } else {
+        fail("More rows returned than expected");
+      }
+      i++;
     }
+  }
 
 }
\ No newline at end of file
diff --git a/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatterTest.java b/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatterTest.java
index d80c036686..bd9dc9a817 100644
--- a/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatterTest.java
+++ b/protocol/src/test/java/com/amazon/opendistroforelasticsearch/sql/protocol/response/format/SimpleJsonResponseFormatterTest.java
@@ -16,104 +16,102 @@
 
 package com.amazon.opendistroforelasticsearch.sql.protocol.response.format;
 
-import com.amazon.opendistroforelasticsearch.sql.protocol.response.QueryResult;
-import com.google.common.collect.ImmutableMap;
-import org.junit.jupiter.api.Disabled;
-import org.junit.jupiter.api.Test;
-
-import java.util.Arrays;
-
 import static com.amazon.opendistroforelasticsearch.sql.data.model.ExprValueUtils.tupleValue;
 import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.COMPACT;
 import static com.amazon.opendistroforelasticsearch.sql.protocol.response.format.JsonResponseFormatter.Style.PRETTY;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
-class SimpleJsonResponseFormatterTest {
+import com.amazon.opendistroforelasticsearch.sql.protocol.response.QueryResult;
+import com.google.common.collect.ImmutableMap;
+import java.util.Arrays;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
 
-    @Test
-    void formatResponse() {
-        QueryResult response = new QueryResult(Arrays.asList(
-            tupleValue(ImmutableMap.of("firstname", "John", "age", 20)),
-            tupleValue(ImmutableMap.of("firstname", "Smith", "age", 30))
-        ));
-        SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
-        assertEquals(
-            "{\"schema\":[{\"name\":\"firstname\",\"type\":\"string\"},{\"name\":\"age\",\"type\":\"integer\"}]," +
-                "\"total\":2,\"datarows\":[[\"John\",20],[\"Smith\",30]],\"size\":2}",
-            formatter.format(response)
-        );
-    }
+class SimpleJsonResponseFormatterTest {
 
-    @Test
-    void formatResponsePretty() {
-        QueryResult response = new QueryResult(Arrays.asList(
-            tupleValue(ImmutableMap.of("firstname", "John", "age", 20)),
-            tupleValue(ImmutableMap.of("firstname", "Smith", "age", 30))
-        ));
-        SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(PRETTY);
-        assertEquals(
-            "{\n" +
-            "  \"schema\": [\n" +
-            "    {\n" +
-            "      \"name\": \"firstname\",\n" +
-            "      \"type\": \"string\"\n" +
-            "    },\n" +
-            "    {\n" +
-            "      \"name\": \"age\",\n" +
-            "      \"type\": \"integer\"\n" +
-            "    }\n" +
-            "  ],\n" +
-            "  \"total\": 2,\n" +
-            "  \"datarows\": [\n" +
-            "    [\n" +
-            "      \"John\",\n" +
-            "      20\n" +
-            "    ],\n" +
-            "    [\n" +
-            "      \"Smith\",\n" +
-            "      30\n" +
-            "    ]\n" +
-            "  ],\n" +
-            "  \"size\": 2\n" +
-            "}",
-            formatter.format(response)
-        );
-    }
+  @Test
+  void formatResponse() {
+    QueryResult response =
+        new QueryResult(
+            Arrays.asList(
+                tupleValue(ImmutableMap.of("firstname", "John", "age", 20)),
+                tupleValue(ImmutableMap.of("firstname", "Smith", "age", 30))));
+    SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
+    assertEquals(
+        "{\"schema\":[{\"name\":\"firstname\",\"type\":\"string\"},"
+            + "{\"name\":\"age\",\"type\":\"integer\"}],"
+            + "\"total\":2,\"datarows\":[[\"John\",20],[\"Smith\",30]],\"size\":2}",
+        formatter.format(response));
+  }
 
-    @Disabled("Need to figure out column headers in some other way than inferring from data implicitly")
-    @Test
-    void formatResponseWithMissingValue() {
-        QueryResult response = new QueryResult(Arrays.asList(
-            tupleValue(ImmutableMap.of("firstname", "John")),
-            tupleValue(ImmutableMap.of("firstname", "Smith", "age", 30))
-        ));
-        SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
-        assertEquals(
-            "{\"schema\":[{\"name\":\"firstname\",\"type\":\"string\"},{\"name\":\"age\",\"type\":\"integer\"}]," +
-                "\"total\":2,\"datarows\":[{\"row\":[\"John\",null]},{\"row\":[\"Smith\",30]}],\"size\":2}",
-            formatter.format(response)
-        );
-    }
+  @Test
+  void formatResponsePretty() {
+    QueryResult response =
+        new QueryResult(
+            Arrays.asList(
+                tupleValue(ImmutableMap.of("firstname", "John", "age", 20)),
+                tupleValue(ImmutableMap.of("firstname", "Smith", "age", 30))));
+    SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(PRETTY);
+    assertEquals(
+        "{\n"
+            + "  \"schema\": [\n"
+            + "    {\n"
+            + "      \"name\": \"firstname\",\n"
+            + "      \"type\": \"string\"\n"
+            + "    },\n"
+            + "    {\n"
+            + "      \"name\": \"age\",\n"
+            + "      \"type\": \"integer\"\n"
+            + "    }\n"
+            + "  ],\n"
+            + "  \"total\": 2,\n"
+            + "  \"datarows\": [\n"
+            + "    [\n"
+            + "      \"John\",\n"
+            + "      20\n"
+            + "    ],\n"
+            + "    [\n"
+            + "      \"Smith\",\n"
+            + "      30\n"
+            + "    ]\n"
+            + "  ],\n"
+            + "  \"size\": 2\n"
+            + "}",
+        formatter.format(response));
+  }
 
-    @Test
-    void formatError() {
-        SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
-        assertEquals(
-            "{\"reason\":\"This is an exception\",\"type\":\"RuntimeException\"}",
-            formatter.format(new RuntimeException("This is an exception"))
-        );
-    }
+  @Disabled("Need to figure out column headers in other way than inferring from data implicitly")
+  @Test
+  void formatResponseWithMissingValue() {
+    QueryResult response =
+        new QueryResult(
+            Arrays.asList(
+                tupleValue(ImmutableMap.of("firstname", "John")),
+                tupleValue(ImmutableMap.of("firstname", "Smith", "age", 30))));
+    SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
+    assertEquals(
+        "{\"schema\":[{\"name\":\"firstname\",\"type\":\"string\"},"
+            + "{\"name\":\"age\",\"type\":\"integer\"}],\"total\":2,"
+            + "\"datarows\":[{\"row\":[\"John\",null]},{\"row\":[\"Smith\",30]}],\"size\":2}",
+        formatter.format(response));
+  }
 
-    @Test
-    void formatErrorPretty() {
-        SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(PRETTY);
-        assertEquals(
-            "{\n" +
-            "  \"reason\": \"This is an exception\",\n" +
-            "  \"type\": \"RuntimeException\"\n" +
-            "}",
-            formatter.format(new RuntimeException("This is an exception"))
-        );
-    }
+  @Test
+  void formatError() {
+    SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(COMPACT);
+    assertEquals(
+        "{\"reason\":\"This is an exception\",\"type\":\"RuntimeException\"}",
+        formatter.format(new RuntimeException("This is an exception")));
+  }
 
-}
\ No newline at end of file
+  @Test
+  void formatErrorPretty() {
+    SimpleJsonResponseFormatter formatter = new SimpleJsonResponseFormatter(PRETTY);
+    assertEquals(
+        "{\n"
+            + "  \"reason\": \"This is an exception\",\n"
+            + "  \"type\": \"RuntimeException\"\n"
+            + "}",
+        formatter.format(new RuntimeException("This is an exception")));
+  }
+}