Support for a java.util.Map implementation backed by ConsistentMap

Change-Id: I73240b69d0913f7534bd4006411ab217a40b254c
diff --git a/core/api/src/main/java/org/onosproject/store/service/ConsistentMap.java b/core/api/src/main/java/org/onosproject/store/service/ConsistentMap.java
index f1ef356..289da20 100644
--- a/core/api/src/main/java/org/onosproject/store/service/ConsistentMap.java
+++ b/core/api/src/main/java/org/onosproject/store/service/ConsistentMap.java
@@ -17,6 +17,7 @@
 package org.onosproject.store.service;
 
 import java.util.Collection;
+import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.function.BiFunction;
@@ -281,4 +282,10 @@
      * @param listener listener to unregister
      */
     void removeListener(MapEventListener<K, V> listener);
-}
+
+    /**
+     * Returns a java.util.Map instance backed by this ConsistentMap.
+     * @return java.util.Map
+     */
+    Map<K, V> asJavaMap();
+}
\ No newline at end of file
diff --git a/core/api/src/test/java/org/onosproject/store/service/ConsistentMapAdapter.java b/core/api/src/test/java/org/onosproject/store/service/ConsistentMapAdapter.java
index e6df572..d0c1adf 100644
--- a/core/api/src/test/java/org/onosproject/store/service/ConsistentMapAdapter.java
+++ b/core/api/src/test/java/org/onosproject/store/service/ConsistentMapAdapter.java
@@ -141,4 +141,9 @@
     public void removeListener(MapEventListener<K, V> listener) {
 
     }
+
+    @Override
+    public Map<K, V> asJavaMap() {
+        return null;
+    }
 }