[ONOS-6324] Add getOrDefault method to ConsistentMap.

Change-Id: Ice7ad6260c6eb8076320ef469874c0c4ceeadc19
diff --git a/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapTest.java b/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapTest.java
index 5d4ef11..23d528b 100644
--- a/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapTest.java
+++ b/core/store/primitives/src/test/java/org/onosproject/store/primitives/resources/impl/AtomixConsistentMapTest.java
@@ -41,6 +41,7 @@
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertThat;
@@ -117,6 +118,16 @@
             assertTrue(result);
         }).join();
 
+        map.getOrDefault("nothing", null).thenAccept(result -> {
+            assertEquals(0, result.version());
+            assertNull(result.value());
+        }).join();
+
+        map.getOrDefault("foo", "bar".getBytes()).thenAccept(result -> {
+            assertEquals(0, result.version());
+            assertArrayEquals("bar".getBytes(), result.value());
+        }).join();
+
         map.put("foo", rawFooValue).thenAccept(result -> {
             assertNull(result);
         }).join();
@@ -164,6 +175,11 @@
             assertTrue(Arrays.equals(Versioned.valueOrElse(result, null), rawFooValue));
         }).join();
 
+        map.getOrDefault("foo", "bar".getBytes()).thenAccept(result -> {
+            assertNotEquals(0, result.version());
+            assertArrayEquals(rawFooValue, result.value());
+        }).join();
+
         map.remove("foo").thenAccept(result -> {
             assertTrue(Arrays.equals(Versioned.valueOrElse(result, null), rawFooValue));
         }).join();