Fix master branch

Change-Id: I99e7a5296ab24fe5d8428a005adafee7d5c6b138
diff --git a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/provider/DefaultVirtualFlowRuleProviderTest.java b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/provider/DefaultVirtualFlowRuleProviderTest.java
index f135464..1a1c235 100644
--- a/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/provider/DefaultVirtualFlowRuleProviderTest.java
+++ b/incubator/net/src/test/java/org/onosproject/incubator/net/virtual/impl/provider/DefaultVirtualFlowRuleProviderTest.java
@@ -78,7 +78,7 @@
 import org.onosproject.net.topology.TopologyCluster;
 import org.onosproject.net.topology.TopologyGraph;
 import org.onosproject.net.topology.TopologyListener;
-import org.onosproject.net.topology.TopologyService;
+import org.onosproject.net.topology.TopologyServiceAdapter;
 
 import java.util.HashSet;
 import java.util.Map;
@@ -476,7 +476,7 @@
         }
     }
 
-    private static class TestTopologyService implements TopologyService {
+    private static class TestTopologyService extends TopologyServiceAdapter {
 
         @Override
         public void addListener(TopologyListener listener) {