T3: Handling null or offline device

Change-Id: Ic93f2844263fea1874b8ff1d2c5f0bc835adcb64
(cherry picked from commit 63a0ac99fedb017a6450c4484620ac29b0462dee)
diff --git a/src/test/java/org/onosproject/t3/impl/T3TestObjects.java b/src/test/java/org/onosproject/t3/impl/T3TestObjects.java
index ff44e43..b1edb86 100644
--- a/src/test/java/org/onosproject/t3/impl/T3TestObjects.java
+++ b/src/test/java/org/onosproject/t3/impl/T3TestObjects.java
@@ -61,6 +61,9 @@
     private static final String HOST_ONE = HOST_ONE_MAC + "/" + HOST_ONE_VLAN;
     private static final String HOST_TWO = HOST_TWO_MAC + "/" + HOST_TWO_VLAN;
 
+    //offline device
+    static final DeviceId OFFLINE_DEVICE = DeviceId.deviceId("offlineDevice");
+
     //Single Flow Test
     static final DeviceId SINGLE_FLOW_DEVICE = DeviceId.deviceId("SingleFlowDevice");
     private static final TrafficSelector SINGLE_FLOW_SELECTOR = DefaultTrafficSelector.builder()