[ONOS-5400][ONOS-5614] identity ref support in yangtools and defect fixes.

Change-Id: Ia1f32a6772e9d468717340953cf7598c61d9f1ed
diff --git a/generator/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedJavaFileType.java b/generator/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedJavaFileType.java
index d05320a..6b14095 100644
--- a/generator/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedJavaFileType.java
+++ b/generator/src/main/java/org/onosproject/yangutils/translator/tojava/GeneratedJavaFileType.java
@@ -99,6 +99,11 @@
     public static final int GENERATE_IDENTITY_CLASS = 2048;
 
     /**
+     * Identity key class.
+     */
+    public static final int GENERATE_KEY_CLASS = 4096;
+
+    /**
      * Creates an instance of generate java file type.
      */
     private GeneratedJavaFileType() {