Add a method for retrieving FlowIdGenerator instance to FlowManagerService.

Change-Id: I65c28c36994f2f1c37e1383977ec6a819225584a
diff --git a/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java b/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java
index 347c5fa..93a4e6c 100644
--- a/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java
+++ b/src/main/java/net/onrc/onos/api/flowmanager/FlowManagerService.java
@@ -62,6 +62,12 @@
     FlowBatchHandle executeBatch(FlowBatchOperation ops);
 
     /**
+     * Gets ID generator for Flow objects.
+     * @return the ID generator for Flow objects
+     */
+    FlowIdGenerator getFlowIdGenerator();
+
+    /**
      * Sets a conflict detection policy.
      *
      * @param policy ConflictDetectionPolicy object to be set