Introduces seen before routes in DefaultRoutingHandler

- to remember the routes that have been visited before

Change-Id: I96470ad5eb0837f7b734ba634c7c3d26e25d03ed
diff --git a/apps/segmentrouting/app/src/test/java/org/onosproject/segmentrouting/DefaultRoutingHandlerTest.java b/apps/segmentrouting/app/src/test/java/org/onosproject/segmentrouting/DefaultRoutingHandlerTest.java
index 28847c6..a6278b2 100644
--- a/apps/segmentrouting/app/src/test/java/org/onosproject/segmentrouting/DefaultRoutingHandlerTest.java
+++ b/apps/segmentrouting/app/src/test/java/org/onosproject/segmentrouting/DefaultRoutingHandlerTest.java
@@ -28,6 +28,7 @@
 import org.onosproject.segmentrouting.config.DeviceConfiguration;
 import org.onosproject.store.service.StorageService;
 import org.onosproject.store.service.TestConsistentMap;
+import org.onosproject.store.service.TestConsistentMultimap;
 
 import java.util.Optional;
 
@@ -57,6 +58,8 @@
         srManager = createMock(SegmentRoutingManager.class);
         srManager.storageService = createMock(StorageService.class);
         expect(srManager.storageService.consistentMapBuilder()).andReturn(new TestConsistentMap.Builder<>()).anyTimes();
+        expect(srManager.storageService.consistentMultimapBuilder()).andReturn(
+                new TestConsistentMultimap.Builder<>()).anyTimes();
         replay(srManager.storageService);
         srManager.routingRulePopulator = createMock(RoutingRulePopulator.class);
         srManager.deviceService = createMock(DeviceService.class);