test enhancements

Change-Id: I28ac2733e6e1ee96810a47500d59d6b54aab3157
diff --git a/core/store/dist/src/test/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStoreTest.java b/core/store/dist/src/test/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStoreTest.java
index 93c40ec..535a095 100644
--- a/core/store/dist/src/test/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStoreTest.java
+++ b/core/store/dist/src/test/java/org/onosproject/store/flowobjective/impl/DistributedFlowObjectiveStoreTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-present Open Networking Laboratory
+ * Copyright 2017-present Open Networking Laboratory
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,8 +24,14 @@
 import org.onosproject.store.service.TestStorageService;
 
 import com.google.common.base.Charsets;
+
+import java.util.Collections;
+
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
 import static org.hamcrest.Matchers.*;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 /**
  * Unit tests for distributed flow objective store.
@@ -49,15 +55,28 @@
 
     @Test
     public void testFlowObjectiveStore() {
+        NextGroup group1 = new DefaultNextGroup("1".getBytes(Charsets.US_ASCII));
         NextGroup group2 = new DefaultNextGroup("2".getBytes(Charsets.US_ASCII));
         int group1Id = store.allocateNextId();
         int group2Id = store.allocateNextId();
 
         NextGroup group1add = store.getNextGroup(group1Id);
         assertThat(group1add, nullValue());
+        NextGroup dif = store.getNextGroup(3);
+        assertThat(dif, is(nullValue()));
 
+
+        store.putNextGroup(group1Id, group1);
         store.putNextGroup(group2Id, group2);
         NextGroup group2Query = store.getNextGroup(group2Id);
         assertThat(group2Query.data(), is(group2.data()));
+        assertTrue(store.getAllGroups().containsKey(group2Id));
+        assertTrue(store.getAllGroups().containsKey(group1Id));
+
+        store.removeNextGroup(group2Id);
+        assertTrue(store.getAllGroups().containsKey(group1Id));
+        assertFalse(store.getAllGroups().containsKey(group2Id));
+        store.removeNextGroup(group1Id);
+        assertEquals(store.getAllGroups(), Collections.emptyMap());
     }
-}
+}
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