removed code duplication in translator, and addressed review comments

Change-Id: I27767a81c4bf279c80d2b98192f75f8f507b4457
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java
index 42b3cc4..18a81e4 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/DefaultListener.java
@@ -45,13 +45,17 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.utils.YangConstructType.DEFAULT_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.MISSING_HOLDER;
 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;
+import static org.onosproject.yangutils.utils.YangConstructType.DEFAULT_DATA;
 
+/**
+ * Listener implementation for default YANG statement.
+ */
 public final class DefaultListener {
 
     /**