[ONOS-4753] Identity/identityref implementation and UT

Change-Id: I40148fa228465555be3bdf410cc294ffc0f34c18
diff --git a/plugin/src/test/resources/interfileidentityincludedependency/featurefile3.yang b/plugin/src/test/resources/interfileidentityincludedependency/featurefile3.yang
new file mode 100644
index 0000000..aa056f0
--- /dev/null
+++ b/plugin/src/test/resources/interfileidentityincludedependency/featurefile3.yang
@@ -0,0 +1,10 @@
+module syslog3 {
+     yang-version 1;
+     namespace "http://huawei3.com";
+     prefix "sys3";
+
+     identity final-address-family {
+         description
+            "Base identity from which specific tunnel types are derived.";
+     }
+}