def METHOD_NAME(num_workers, num_ps, protocol="grpc"):
  """Create local GRPC servers and return them."""
  worker_ports = [portpicker.pick_unused_port() for _ in range(num_workers)]
  ps_ports = [portpicker.pick_unused_port() for _ in range(num_ps)]
  cluster_dict = {
      "worker": ["localhost:%s" % port for port in worker_ports],
      "ps": ["localhost:%s" % port for port in ps_ports]
  }
  cs = server_lib.ClusterSpec(cluster_dict)
  workers = [
      server_lib.Server(
          cs, job_name="worker", protocol=protocol, task_index=ix, start=True)
      for ix in range(num_workers)
  ]
  ps_servers = [
      server_lib.Server(
          cs, job_name="ps", protocol=protocol, task_index=ix, start=True)
      for ix in range(num_ps)
  ]
  return cluster_dict, workers, ps_servers