StorageService API for creating AsyncDocumentTree primitive

Change-Id: Ib7c3f19beb7b26a5b69161cf972c3c64d0be94b3
diff --git a/core/api/src/test/java/org/onosproject/store/service/StorageServiceAdapter.java b/core/api/src/test/java/org/onosproject/store/service/StorageServiceAdapter.java
index e75c59e..01cc065 100644
--- a/core/api/src/test/java/org/onosproject/store/service/StorageServiceAdapter.java
+++ b/core/api/src/test/java/org/onosproject/store/service/StorageServiceAdapter.java
@@ -64,7 +64,13 @@
         return null;
     }
 
+    @Override
     public <V> ConsistentTreeMapBuilder<V> consistentTreeMapBuilder() {
         return null;
     }
+
+    @Override
+    public <V> AsyncDocumentTree<V> getDocumentTree(String name, Serializer serializer) {
+        return null;
+    }
 }