diff --git a/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java b/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java
index 2e5036b..5e599c3 100644
--- a/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java
+++ b/asterix-common/src/test/java/edu/uci/ics/asterix/test/aql/TestsUtils.java
@@ -348,11 +348,6 @@
 
             for (TestFileContext ctx : testFileCtxs) {
                 testFile = ctx.getFile();
-                /*
-                if(!testFile.getName().contains("423")){
-                	continue;
-                }
-                */
                 statement = TestsUtils.readTestFile(testFile);
                 try {
                     switch (ctx.getType()) {
@@ -401,3 +396,4 @@
 
     }
 }
+
diff --git a/asterix-om/src/main/java/edu/uci/ics/asterix/formats/nontagged/AqlPredicateEvaluatorFactoryProvider.java b/asterix-om/src/main/java/edu/uci/ics/asterix/formats/nontagged/AqlPredicateEvaluatorFactoryProvider.java
index 11c918a..f4fa74e 100644
--- a/asterix-om/src/main/java/edu/uci/ics/asterix/formats/nontagged/AqlPredicateEvaluatorFactoryProvider.java
+++ b/asterix-om/src/main/java/edu/uci/ics/asterix/formats/nontagged/AqlPredicateEvaluatorFactoryProvider.java
@@ -1,3 +1,18 @@
+/*
+ * Copyright 2009-2013 by The Regents of the University of California
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * you may obtain a copy of the License from
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package edu.uci.ics.asterix.formats.nontagged;
 
 import edu.uci.ics.asterix.om.types.ATypeTag;
@@ -6,16 +21,21 @@
 import edu.uci.ics.hyracks.api.dataflow.value.IPredicateEvaluator;
 import edu.uci.ics.hyracks.api.dataflow.value.IPredicateEvaluatorFactory;
 import edu.uci.ics.hyracks.api.dataflow.value.IPredicateEvaluatorFactoryProvider;
-import edu.uci.ics.hyracks.dataflow.common.comm.io.FrameTupleAccessor;
 
+/*
+Provides PredicateEvaluator for equi-join cases to properly take care of NULL fields, being compared with each other.
+If any of the join keys, from either side, is NULL, record should not pass equi-join condition.
+*/
 public class AqlPredicateEvaluatorFactoryProvider implements IPredicateEvaluatorFactoryProvider{
 	
+	private static final long serialVersionUID = 1L;
 	public static final AqlPredicateEvaluatorFactoryProvider INSTANCE = new AqlPredicateEvaluatorFactoryProvider();
 	
 	@Override
 	public IPredicateEvaluatorFactory getPredicateEvaluatorFactory(final int[] keys0, final int[] keys1) {
 		
 		return new IPredicateEvaluatorFactory() {
+			private static final long serialVersionUID = 1L;
 			@Override
 			public IPredicateEvaluator createPredicateEvaluator() {
 				return new IPredicateEvaluator() {