Distributed topic primitive

Change-Id: Ia3ccd84c33075f297d7e6b9bc205efe92aec9bea
diff --git a/core/api/src/main/java/org/onosproject/store/service/StorageService.java b/core/api/src/main/java/org/onosproject/store/service/StorageService.java
index 1e006eb..ebc60d1 100644
--- a/core/api/src/main/java/org/onosproject/store/service/StorageService.java
+++ b/core/api/src/main/java/org/onosproject/store/service/StorageService.java
@@ -110,4 +110,15 @@
      * @return WorkQueue instance
      */
     <E> WorkQueue<E> getWorkQueue(String name, Serializer serializer);
+
+    /**
+     * Returns an instance of {@code Topic} with specified name.
+     *
+     * @param <E> topic message type
+     * @param name topic name
+     * @param serializer serializer
+     *
+     * @return Topic instance
+     */
+    <T> Topic<T> getTopic(String name, Serializer serializer);
 }