Enahnced topology and flow stores to extend general store.
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStore.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStore.java
index f00b595..bfd05f2 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStore.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStore.java
@@ -1,11 +1,12 @@
 package org.onlab.onos.net.flow;
 
 import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.store.Store;
 
 /**
  * Manages inventory of flow rules; not intended for direct use.
  */
-public interface FlowRuleStore {
+public interface FlowRuleStore extends Store<FlowRuleEvent, FlowRuleStoreDelegate> {
 
     /**
      * Returns the flow entries associated with a device.
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStoreDelegate.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStoreDelegate.java
new file mode 100644
index 0000000..119712b
--- /dev/null
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowRuleStoreDelegate.java
@@ -0,0 +1,9 @@
+package org.onlab.onos.net.flow;
+
+import org.onlab.onos.store.StoreDelegate;
+
+/**
+ * Flow rule store delegate abstraction.
+ */
+public interface FlowRuleStoreDelegate extends StoreDelegate<FlowRuleEvent> {
+}