More Unit tests

Change-Id: I32dd3851e490979621c4a5205c6e041dee900244
diff --git a/core/store/dist/src/main/java/org/onosproject/store/ecmap/EventuallyConsistentMapImpl.java b/core/store/dist/src/main/java/org/onosproject/store/ecmap/EventuallyConsistentMapImpl.java
index 2de8947..b56d74b 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/ecmap/EventuallyConsistentMapImpl.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/ecmap/EventuallyConsistentMapImpl.java
@@ -653,7 +653,7 @@
         public void processItems(List<UpdateEntry<K, V>> items) {
             Map<K, UpdateEntry<K, V>> map = Maps.newHashMap();
             items.forEach(item -> map.compute(item.key(), (key, existing) ->
-                    existing == null || item.compareTo(existing) > 0 ? item : existing));
+                    item.isNewerThan(existing) ? item : existing));
             communicationExecutor.submit(() -> {
                 clusterCommunicator.unicast(ImmutableList.copyOf(map.values()),
                                             updateMessageSubject,