code: def _host_notification(self, context, method, payload, host):
          
          LOG.debug('Notify Cisco cfg agent at %(host)s the message '
                    '%(method)s', {'host': host, 'method': method})
          cctxt = self.client.prepare(server=host)
          cctxt.cast(context, method, payload=payload)
docs: Notify the cfg agent that is handling the hosting device.