diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
index e957a9d1..6c31658a 100644
--- a/.github/workflows/build-and-test.yml
+++ b/.github/workflows/build-and-test.yml
@@ -5,17 +5,20 @@ on:
     branches:
       - main
   pull_request:
-    
+
 jobs:
   build-and-test:
+    name: Test using Java ${{ matrix.java }}
     runs-on: ubuntu-latest
-
+    strategy:
+      matrix:
+        java: [ '8', '11', '17', '19' ]
     steps:
     - uses: actions/checkout@v3
-    - name: Set up JDK 8
+    - name: Set up JDK ${{ matrix.java }}
       uses: actions/setup-java@v3
       with:
-        java-version: '8'
+        java-version: ${{ matrix.java }}
         distribution: 'temurin'
         cache: maven
     - name: Build with Maven
diff --git a/pom.xml b/pom.xml
index f43710f9..1b7e590e 100644
--- a/pom.xml
+++ b/pom.xml
@@ -228,6 +228,9 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-javadoc-plugin</artifactId>
 				<version>2.9.1</version>
+				<configuration>
+				  <source>8</source>
+				</configuration>
 				<executions>
 					<execution>
 						<id>attach-javadocs</id>
diff --git a/src/main/java/io/apimatic/core/utilities/TestHelper.java b/src/main/java/io/apimatic/core/utilities/TestHelper.java
index d4bf5cc3..5a347f48 100644
--- a/src/main/java/io/apimatic/core/utilities/TestHelper.java
+++ b/src/main/java/io/apimatic/core/utilities/TestHelper.java
@@ -227,7 +227,7 @@ private static boolean isProperSubsetOf(
      * @param allowExtra extra value is allowed?.
      * @param isOrdered object value is in order?.
      * @throws IOException Signal that I/O errors occur.
-     * @return <tt>true</tt> if left left JSON object is a proper subset of right JSON object.
+     * @return true if left left JSON object is a proper subset of right JSON object.
      */
     public static boolean isJsonObjectProperSubsetOf(
             String leftObject, String rightObject, boolean checkValues, boolean allowExtra,
@@ -441,7 +441,7 @@ private static boolean isListProperSubsetOf(
      * @param leftTree Left headers map.
      * @param rightTree Right headers map.
      * @param checkValues Check header values for equality?.
-     * @return <tt>true</tt> if left headers map is a proper subset of right headers map.
+     * @return true if left headers map is a proper subset of right headers map.
      */
     public static boolean areHeadersProperSubsetOf(
             Map<String, String> leftTree, Map<String, String> rightTree, boolean checkValues) {