Change DefaultRouteTable primitive to cached multimap.

Change-Id: I4b29f95894a5f761a59bebbd9aa6ea778a128f22
diff --git a/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapTest.java b/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapTest.java
index dbfd051..0247fca 100644
--- a/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapTest.java
+++ b/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentSetMultimapTest.java
@@ -167,7 +167,7 @@
 
         //Check that contains key works properly for removed keys
         map.containsKey(removedKey[0])
-                .thenAccept(result -> assertFalse(result));
+                .thenAccept(result -> assertFalse(result)).join();
 
         //Check that contains value works correctly for removed values
         allValues.forEach(value -> {