diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java
index 3f60aef..8cd6d67 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/RevisionDateListener.java
@@ -19,14 +19,16 @@
 import org.onosproject.yangutils.datamodel.YangImport;
 import org.onosproject.yangutils.datamodel.YangInclude;
 import org.onosproject.yangutils.parser.Parsable;
-import org.onosproject.yangutils.parser.ParsableDataType;
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType;
-import org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation;
+
+import static org.onosproject.yangutils.parser.ParsableDataType.REVISION_DATE_DATA;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerValidation.checkStackIsNotEmpty;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -57,8 +59,9 @@
  */
 
 /**
- * Implements listener based call back function corresponding to the "revision date"
- * rule defined in ANTLR grammar file for corresponding ABNF rule in RFC 6020.
+ * Implements listener based call back function corresponding to the
+ * "revision date" rule defined in ANTLR grammar file for corresponding ABNF
+ * rule in RFC 6020.
  */
 public final class RevisionDateListener {
 
@@ -69,9 +72,8 @@
     }
 
     /**
-     * It is called when parser receives an input matching the grammar
-     * rule (revision date),perform validations and update the data model
-     * tree.
+     * It is called when parser receives an input matching the grammar rule
+     * (revision date),perform validations and update the data model tree.
      *
      * @param listener Listener's object.
      * @param ctx context object of the grammar rule.
@@ -80,10 +82,8 @@
                                                 GeneratedYangParser.RevisionDateStatementContext ctx) {
 
         // Check for stack to be non empty.
-        ListenerValidation.checkStackIsNotEmpty(listener, ListenerErrorType.MISSING_HOLDER,
-                                                ParsableDataType.REVISION_DATE_DATA,
-                                                String.valueOf(ctx.DATE_ARG().getText()),
-                                                ListenerErrorLocation.ENTRY);
+        checkStackIsNotEmpty(listener, MISSING_HOLDER, REVISION_DATE_DATA, String.valueOf(ctx.DATE_ARG().getText()),
+                             ENTRY);
 
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
@@ -99,13 +99,9 @@
             break;
         }
         default:
-            throw new ParserException(
-                                      ListenerErrorMessageConstruction
-                                              .constructListenerErrorMessage(ListenerErrorType.INVALID_HOLDER,
-                                                                             ParsableDataType.REVISION_DATE_DATA,
-                                                                             String.valueOf(ctx.DATE_ARG().getText()),
-                                                                             ListenerErrorLocation.ENTRY));
+            throw new ParserException(constructListenerErrorMessage(INVALID_HOLDER, REVISION_DATE_DATA,
+                                                                    String.valueOf(ctx.DATE_ARG().getText()), ENTRY));
         }
     }
     // TODO Implement the DATE_ARG validation as per RFC 6020.
-}
\ No newline at end of file
+}