Initial sketch of the virtual network constructs.

Change-Id: Ibcdafb9e56edb29fb37b80d7b0da321ad989c564
diff --git a/core/api/src/main/java/org/onosproject/net/behaviour/PortConfig.java b/core/api/src/main/java/org/onosproject/net/behaviour/PortConfig.java
index 464698e..7de2861 100644
--- a/core/api/src/main/java/org/onosproject/net/behaviour/PortConfig.java
+++ b/core/api/src/main/java/org/onosproject/net/behaviour/PortConfig.java
@@ -17,11 +17,12 @@
 
 import com.google.common.primitives.UnsignedInteger;
 import org.onosproject.net.device.PortDescription;
+import org.onosproject.net.driver.HandlerBehaviour;
 
 /**
  * Means to configure a logical port at the device.
  */
-public interface PortConfig {
+public interface PortConfig extends HandlerBehaviour {
 
     /**
      * Apply QoS configuration on a device.