[ONOS-4616] grouping linker issues fixed and other defect fixed.

Change-Id: I1b23f9ed0293edbc2d551efe82982559eb916ede
diff --git a/utils/yangutils/src/test/resources/IdentityrefInvalidIdentifier.yang b/utils/yangutils/src/test/resources/IdentityrefInvalidIdentifier.yang
new file mode 100644
index 0000000..99a8129
--- /dev/null
+++ b/utils/yangutils/src/test/resources/IdentityrefInvalidIdentifier.yang
@@ -0,0 +1,11 @@
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    grouping currentcheck {
+        leaf invalid-interval {
+            type identityref {
+            }
+        }
+    }
+}