Distributed topic primitive

Change-Id: Ia3ccd84c33075f297d7e6b9bc205efe92aec9bea
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 3978614..0cd1b60 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
@@ -58,4 +58,9 @@
     public <E> WorkQueue<E> getWorkQueue(String name, Serializer serializer) {
         return null;
     }
+
+    @Override
+    public <T> Topic<T> getTopic(String name, Serializer serializer) {
+        return null;
+    }
 }