move isConnected to OpenFlowSwitch interface

Change-Id: I08d1746dc05464135cabe31888f6bb3eac9c15d5
diff --git a/providers/openflow/link/src/test/java/org/onlab/onos/provider/of/link/impl/OpenFlowLinkProviderTest.java b/providers/openflow/link/src/test/java/org/onlab/onos/provider/of/link/impl/OpenFlowLinkProviderTest.java
index 4109ba0..a6b0ac3 100644
--- a/providers/openflow/link/src/test/java/org/onlab/onos/provider/of/link/impl/OpenFlowLinkProviderTest.java
+++ b/providers/openflow/link/src/test/java/org/onlab/onos/provider/of/link/impl/OpenFlowLinkProviderTest.java
@@ -475,6 +475,11 @@
         }
 
         @Override
+        public boolean isConnected() {
+            return true;
+        }
+
+        @Override
         public void disconnectSwitch() {
         }