code: def get_cfg_router_ids(self, context, host, router_ids=None,
                         hosting_device_ids=None):
          
          return self._l3plugin.cfg_list_router_ids_on_host(context, host,
                                                        router_ids,
                                                        hosting_device_ids)
docs: Returns IDs of routers scheduled to l3 agent on <host>