code: def on_controller_change(self, name, value):
          
          if self.__controller != name:
              # Nothing to do
              return
  
          # Update the controller value
          self.__controller_on = value
          if value:
              # Controller switched to "ON"
              self._register_service()
          else:
              # Controller switched to "OFF"
              self._unregister_service()
docs: Called by the instance manager when a controller value has been
          modified
  
          :param name: The name of the controller
          :param value: The new value of the controller