code: def test_multi_client_connect():
      reset_envs()
      os.environ["DGL_DIST_MODE"] = "distributed"
      ip_config = "rpc_ip_config_mul_client.txt"
      generate_ip_config(ip_config, 1, 1)
      ctx = mp.get_context("spawn")
      num_clients = 1
      pserver = ctx.Process(
          target=start_server,
          args=(num_clients, ip_config, 0, 1),
      )
  
      # small max try times
      os.environ["DGL_DIST_MAX_TRY_TIMES"] = "1"
      expect_except = False
      try:
          start_client(ip_config, 0, 1)
      except dgl.distributed.DistConnectError as err:
          print("Expected error: {}".format(err))
          expect_except = True
      assert expect_except
  
      # large max try times
      os.environ["DGL_DIST_MAX_TRY_TIMES"] = "1024"
      pclient = ctx.Process(target=start_client, args=(ip_config, 0, 1))
      pclient.start()
      pserver.start()
      pclient.join()
      pserver.join()
      reset_envs()
  
imports: import multiprocessing
  import os
  import socket
  import time
  import unittest
  import backend
  import dgl
  import pytest
  from numpy.testing import assert_array_equal
  from utils import generate_ip_config, reset_envs
label_desc: Use image node_id 11 for calling a global function with example usage: test_multi_client_connect() without return types