YANG construct collision detection framework added

Change-Id: I1458f9e3192641f3f90c444798c31a64536ffa5d
diff --git a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java
index fc9793f..c938190 100644
--- a/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java
+++ b/src/main/java/org/onosproject/yangutils/parser/impl/listeners/BelongsToListener.java
@@ -22,13 +22,14 @@
 import org.onosproject.yangutils.parser.antlrgencode.GeneratedYangParser;
 import org.onosproject.yangutils.parser.exceptions.ParserException;
 import org.onosproject.yangutils.parser.impl.TreeWalkListener;
-
-import static org.onosproject.yangutils.parser.ParsableDataType.BELONGS_TO_DATA;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.ENTRY;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorLocation.EXIT;
 import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorMessageConstruction.constructListenerErrorMessage;
-import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.*;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.INVALID_HOLDER;
+import static org.onosproject.yangutils.parser.impl.parserutils.ListenerErrorType.MISSING_CURRENT_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.BELONGS_TO_DATA;
 
 /*
  * Reference: RFC6020 and YANG ANTLR Grammar
@@ -70,8 +71,8 @@
      * It is called when parser receives an input matching the grammar rule
      * (belongsto), 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 processBelongsToEntry(TreeWalkListener listener,
                                              GeneratedYangParser.BelongstoStatementContext ctx) {
@@ -91,8 +92,8 @@
      * It is called when parser exits from grammar rule (belongsto), it 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 processBelongsToExit(TreeWalkListener listener,
                                             GeneratedYangParser.BelongstoStatementContext ctx) {
@@ -110,7 +111,7 @@
                                  ctx.IDENTIFIER().getText(), EXIT);
 
             Parsable tmpNode = listener.getParsedDataStack().peek();
-            switch (tmpNode.getParsableDataType()) {
+            switch (tmpNode.getYangConstructType()) {
             case SUB_MODULE_DATA: {
                 YangSubModule subModule = (YangSubModule) tmpNode;
                 subModule.setBelongsTo((YangBelongsTo) tmpBelongstoNode);