YANG construct collision detection framework added

Change-Id: I1458f9e3192641f3f90c444798c31a64536ffa5d
diff --git a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java
index 021ae0d..9b9a388 100644
--- a/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java
+++ b/utils/yangutils/src/main/java/org/onosproject/yangutils/parser/impl/listeners/VersionListener.java
@@ -23,7 +23,7 @@
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
 
-import static org.onosproject.yangutils.parser.ParsableDataType.VERSION_DATA;
+import static org.onosproject.yangutils.utils.YangConstructType.VERSION_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;
@@ -78,8 +78,8 @@
      * It is called when parser receives an input matching the grammar rule
      * (version), perform validations and update the data model tree.
      *
-     * @param listener Listener's object.
-     * @param ctx context object of the grammar rule.
+     * @param listener Listener's object
+     * @param ctx context object of the grammar rule
      */
     public static void processVersionEntry(TreeWalkListener listener,
                                            GeneratedYangParser.YangVersionStatementContext ctx) {
@@ -89,7 +89,7 @@
 
         Integer version = Integer.valueOf(ctx.INTEGER().getText());
         if (!isVersionValid(version)) {
-            ParserException parserException = new ParserException("Input version not supported");
+            ParserException parserException = new ParserException("YANG file error: Input version not supported");
             parserException.setLine(ctx.INTEGER().getSymbol().getLine());
             parserException.setCharPosition(ctx.INTEGER().getSymbol().getCharPositionInLine());
             throw parserException;
@@ -97,7 +97,7 @@
 
         // Obtain the node of the stack.
         Parsable tmpNode = listener.getParsedDataStack().peek();
-        switch (tmpNode.getParsableDataType()) {
+        switch (tmpNode.getYangConstructType()) {
         case MODULE_DATA: {
             YangModule module = (YangModule) tmpNode;
             module.setVersion((byte) 1);