diff --git a/src/main/java/org/apache/datasketches/memory/AllocateDirect.java b/src/main/java/org/apache/datasketches/memory/AllocateDirect.java
index e699e1fe..423c0742 100644
--- a/src/main/java/org/apache/datasketches/memory/AllocateDirect.java
+++ b/src/main/java/org/apache/datasketches/memory/AllocateDirect.java
@@ -24,7 +24,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import sun.misc.Cleaner;
+import sun.misc.Cleaner;         //JDK 8
+//import jdk.internal.ref.Cleaner;   //JDK 9+
 
 /**
  * Provides access to direct (native) memory.
@@ -34,9 +35,9 @@
  */
 final class AllocateDirect implements AutoCloseable {
   private static final Logger LOG = LoggerFactory.getLogger(AllocateDirect.class);
-
+  
   private final Deallocator deallocator;
-  private final Cleaner cleaner; //TODO-JDK9 import jdk.internal.ref.Cleaner;
+  private final Cleaner cleaner;
   private final long nativeBaseOffset;
 
   /**
@@ -60,14 +61,14 @@ final class AllocateDirect implements AutoCloseable {
       NioBits.unreserveMemory(allocationSize, capacityBytes);
       throw err;
     }
-    if (pageAligned && ((nativeAddress % pageSize) != 0)) {
+    if (pageAligned && nativeAddress % pageSize != 0) {
       //Round up to page boundary
       nativeBaseOffset = (nativeAddress & ~(pageSize - 1L)) + pageSize;
     } else {
       nativeBaseOffset = nativeAddress;
     }
     deallocator = new Deallocator(nativeAddress, allocationSize, capacityBytes);
-    cleaner = Cleaner.create(this, deallocator);
+      cleaner = Cleaner.create(this, deallocator);
   }
 
   @Override
@@ -112,7 +113,7 @@ private Deallocator(final long nativeAddress, final long allocationSize, final l
       this.nativeAddress = nativeAddress;
       this.allocationSize = allocationSize;
       this.capacity = capacity;
-      assert (nativeAddress != 0);
+      assert nativeAddress != 0;
     }
 
     StepBoolean getValid() {
diff --git a/src/main/java/org/apache/datasketches/memory/AllocateDirectMap.java b/src/main/java/org/apache/datasketches/memory/AllocateDirectMap.java
index 41cdf46c..a7f6d8c0 100644
--- a/src/main/java/org/apache/datasketches/memory/AllocateDirectMap.java
+++ b/src/main/java/org/apache/datasketches/memory/AllocateDirectMap.java
@@ -33,7 +33,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import sun.misc.Cleaner; //TODO-JDK9 jdk.internal.ref.Cleaner;
+import sun.misc.Cleaner;         //JDK 8
+//import jdk.internal.ref.Cleaner;   //JDK 9+
 import sun.nio.ch.FileChannelImpl;
 
 /**
diff --git a/src/test/java/org/apache/datasketches/memory/UnsafeUtilTest.java b/src/test/java/org/apache/datasketches/memory/UnsafeUtilTest.java
index 5a5aaebd..e571d59d 100644
--- a/src/test/java/org/apache/datasketches/memory/UnsafeUtilTest.java
+++ b/src/test/java/org/apache/datasketches/memory/UnsafeUtilTest.java
@@ -53,6 +53,11 @@ public void checkJDK7methods() {
     }
   }
 
+  @Test
+  public void checkJDK_MAJOR() {
+    println(UnsafeUtil.JDK_MAJOR);
+  }
+
   @Test
   public void checkJdkString() {
     String jdkVer;
@@ -63,7 +68,7 @@ public void checkJdkString() {
       jdkVer = good1_8Strings[i];
       p = UnsafeUtil.parseJavaVersion(jdkVer);
       UnsafeUtil.checkJavaVersion(jdkVer, p[0], p[1]);
-      int jdkMajor = (p[0] == 1) ? p[1] : p[0]; //model the actual JDK_MAJOR
+      int jdkMajor = p[0] == 1 ? p[1] : p[0]; //model the actual JDK_MAJOR
       if (p[0] == 1) { assertTrue(jdkMajor == p[1]); }
       if (p[0] > 1 ) { assertTrue(jdkMajor == p[0]); }
     }
@@ -156,10 +161,10 @@ public void printlnTest() {
   }
 
   /**
-   * @param s String to print
+   * @param o String to print
    */
-  static void println(final String s) {
-    //System.out.println(s);
+  static void println(final Object o) {
+    //System.out.println(o.toString());
   }
 
 }