ONOS-686, 687, 1344 : The first commit for the Segment Routing application
 - ICMP/ARP/IP handlers are implemented as a part of the application for now
 - Default routing and link add/failure/recovery are also supprted
 - Temporary NetworkConfigHandler, which is hardcoded to support only 6 router FISH topology, is used for test
 - Some fixes on GroupHanlder app to support transit routers
 - Supports multi-instance (tested with two instances)

Change-Id: Idfa67903e59e1c4cac4da430f89cd4c50e821420
diff --git a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java
index 1b5bb50..b820b09 100644
--- a/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java
+++ b/apps/grouphandler/src/main/java/org/onosproject/grouphandler/DefaultTransitGroupHandler.java
@@ -138,7 +138,8 @@
                                             Set<DeviceId> updatedNeighbors) {
         Set<Set<DeviceId>> powerSet = getPowerSetOfNeighbors(updatedNeighbors);
 
-        Set<DeviceId> tmp = updatedNeighbors;
+        Set<DeviceId> tmp = new HashSet<DeviceId>();
+        tmp.addAll(updatedNeighbors);
         tmp.remove(impactedNeighbor);
         Set<Set<DeviceId>> tmpPowerSet = getPowerSetOfNeighbors(tmp);