Optimizing Generate Code Function in Translator and updating enum/union to support a special hierarchical scenario

Change-Id: I14a971ff6fcda6ae5e86ffe4c11d17a844e371ce
diff --git a/src/main/java/org/onosproject/yangutils/datamodel/YangNodeType.java b/src/main/java/org/onosproject/yangutils/datamodel/YangNodeType.java
index 174ca39..35fe918 100644
--- a/src/main/java/org/onosproject/yangutils/datamodel/YangNodeType.java
+++ b/src/main/java/org/onosproject/yangutils/datamodel/YangNodeType.java
@@ -95,6 +95,11 @@
     RPC_NODE,
 
     /**
+     * Node contains "YANG's union" information.
+     */
+    UNION_NODE,
+
+    /**
      * Node contains "YANG's list" information.
      */
     LIST_NODE