[Falcon][ONOS-3537] Implement control message collecting logic w/ unit test

Change-Id: Ic21d476a5ad92d7ef739fa3c13dcc06e5cbf7c56
diff --git a/protocols/openflow/ctl/src/test/java/org/onosproject/openflow/OpenflowSwitchDriverAdapter.java b/protocols/openflow/ctl/src/test/java/org/onosproject/openflow/OpenflowSwitchDriverAdapter.java
index 9b899a6..b1b77d8 100644
--- a/protocols/openflow/ctl/src/test/java/org/onosproject/openflow/OpenflowSwitchDriverAdapter.java
+++ b/protocols/openflow/ctl/src/test/java/org/onosproject/openflow/OpenflowSwitchDriverAdapter.java
@@ -22,6 +22,7 @@
 import org.onosproject.net.driver.DriverData;
 import org.onosproject.net.driver.DriverHandler;
 import org.onosproject.openflow.controller.Dpid;
+import org.onosproject.openflow.controller.OpenFlowEventListener;
 import org.onosproject.openflow.controller.RoleState;
 import org.onosproject.openflow.controller.driver.OpenFlowAgent;
 import org.onosproject.openflow.controller.driver.OpenFlowSwitchDriver;
@@ -299,4 +300,12 @@
     public String channelId() {
         return null;
     }
+
+    @Override
+    public void addEventListener(OpenFlowEventListener listener) {
+    }
+
+    @Override
+    public void removeEventListener(OpenFlowEventListener listener) {
+    }
 }