Enahnced topology and flow stores to extend general store.
diff --git a/core/api/src/main/java/org/onlab/onos/net/topology/TopologyStore.java b/core/api/src/main/java/org/onlab/onos/net/topology/TopologyStore.java
index adc6145..1945f4c 100644
--- a/core/api/src/main/java/org/onlab/onos/net/topology/TopologyStore.java
+++ b/core/api/src/main/java/org/onlab/onos/net/topology/TopologyStore.java
@@ -6,6 +6,7 @@
 import org.onlab.onos.net.Link;
 import org.onlab.onos.net.Path;
 import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.store.Store;
 
 import java.util.List;
 import java.util.Set;
@@ -13,7 +14,7 @@
 /**
  * Manages inventory of topology snapshots; not intended for direct use.
  */
-public interface TopologyStore {
+public interface TopologyStore extends Store<TopologyEvent, TopologyStoreDelegate> {
 
     /**
      * Returns the current topology snapshot.