code: def publish_changes(self, etype, echid):
          
          _LOGGING.debug('%s Update: %s, %s',
                         self.name, etype, self.fetch_attributes(etype, echid))
          signal = 'ValueChanged.{}'.format(self.cam_id)
          sender = '{}.{}'.format(etype, echid)
          if dispatcher:
              dispatcher.send(signal=signal, sender=sender)
  
          self._do_update_callback('{}.{}.{}'.format(self.cam_id, etype, echid))
docs: Post updates for specified event type.