[ONOS-3535] Accumulate control message stats using monitor service

- Augment the control message class to have device id
- Initial implementation of accumulating control message stats
- Add more adpator for unit test
- Change Collection<ControlMessage> to Set<ControlMessage>
- Fix the arithmatic exception
- Fix some javadoc warnings

Change-Id: I2abaf0d91edca5419b26f1c5a69246bcdb9201bf
diff --git a/apps/cpman/api/src/main/java/org/onosproject/cpman/message/ControlMessageProviderService.java b/apps/cpman/api/src/main/java/org/onosproject/cpman/message/ControlMessageProviderService.java
index 7a702c2..0472a2f 100644
--- a/apps/cpman/api/src/main/java/org/onosproject/cpman/message/ControlMessageProviderService.java
+++ b/apps/cpman/api/src/main/java/org/onosproject/cpman/message/ControlMessageProviderService.java
@@ -19,7 +19,7 @@
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.provider.ProviderService;
 
-import java.util.Collection;
+import java.util.Set;
 
 /**
  * Service through which control message providers can inject control message
@@ -34,5 +34,5 @@
      * @param deviceId device identifier
      * @param controlMessages a collection of control message stats
      */
-    void updateStatsInfo(DeviceId deviceId, Collection<ControlMessage> controlMessages);
+    void updateStatsInfo(DeviceId deviceId, Set<ControlMessage> controlMessages);
 }
\ No newline at end of file