move isConnected to OpenFlowSwitch interface

Change-Id: I08d1746dc05464135cabe31888f6bb3eac9c15d5
diff --git a/openflow/api/src/main/java/org/onlab/onos/openflow/controller/OpenFlowSwitch.java b/openflow/api/src/main/java/org/onlab/onos/openflow/controller/OpenFlowSwitch.java
index 77eb437..2d3f890 100644
--- a/openflow/api/src/main/java/org/onlab/onos/openflow/controller/OpenFlowSwitch.java
+++ b/openflow/api/src/main/java/org/onlab/onos/openflow/controller/OpenFlowSwitch.java
@@ -115,6 +115,13 @@
     public String serialNumber();
 
     /**
+     * Checks if the switch is still connected.
+     *
+     * @return whether the switch is still connected
+     */
+    public boolean isConnected();
+
+    /**
      * Disconnects the switch by closing the TCP connection. Results in a call
      * to the channel handler's channelDisconnected method for cleanup
      */