Added DistributedPrimitive interface
Added AsyncDistributedSet that provides async set operations

Change-Id: I83494075a7973694ea6b7445ff4799b7a1a50641
diff --git a/core/api/src/main/java/org/onosproject/store/service/DistributedSetBuilder.java b/core/api/src/main/java/org/onosproject/store/service/DistributedSetBuilder.java
index f5a44c9..09ba794 100644
--- a/core/api/src/main/java/org/onosproject/store/service/DistributedSetBuilder.java
+++ b/core/api/src/main/java/org/onosproject/store/service/DistributedSetBuilder.java
@@ -129,4 +129,13 @@
      * @throws java.lang.RuntimeException if a mandatory parameter is missing
      */
     DistributedSet<E> build();
+
+    /**
+     * Builds an {@link AsyncDistributedSet async set} based on the configuration options
+     * supplied to this builder.
+     *
+     * @return new AsyncDistributedSet
+     * @throws java.lang.RuntimeException if a mandatory parameter is missing
+     */
+    AsyncDistributedSet<E> buildAsyncSet();
 }