code: def _agent_notification_bulk(self, context, method, routers,
                                   hosting_device, operation):
          
          admin_context = context.is_admin and context or context.elevated()
          dmplugin = bc.get_plugin(cisco_constants.DEVICE_MANAGER)
          if (hosting_device is not None and extensions.is_extension_supported(
                  dmplugin, CFGAGENT_SCHED)):
              agents = dmplugin.get_cfg_agents_for_hosting_devices(
                  admin_context, [hosting_device['id']], admin_state_up=True,
                  schedule=True)
              if agents:
                  agent = agents[0]
                  LOG.debug('Notify %(agent_type)s at %(topic)s.%(host)s the '
                            'message %(method)s [BULK]',
                            {'agent_type': agent.agent_type,
                             'topic': CFG_AGENT_L3_ROUTING,
                             'host': agent.host,
                             'method': method})
                  cctxt = self.client.prepare(server=agent.host,
                                              version='1.1')
                  cctxt.cast(context, method, routers=routers)
docs: Notify the Cisco cfg agent handling a particular hosting_device.
  
          A single notification can contain multiple routers.