code: public void removeListener(Class<? extends VehicleMessage> messageType,
              VehicleMessage.Listener listener) {
          mNotifier.unregister(messageType, listener);
      }
docs: Unregister a previously registered message type listener.
  
  @param messageType The class of the VehicleMessage this listener was
  registered to receive. A listener can be registered to receive
  multiple message types, which is why this must be specified when
  removing a listener.
  @param listener The listener to remove.