code: def test_socket_error():
      tracker = RabitTracker(host_ip="127.0.0.1", n_workers=1)
      tracker.start(1)
      env = tracker.worker_envs()
      env["DMLC_TRACKER_PORT"] = 0
      env["DMLC_WORKER_CONNECT_RETRY"] = 1
      with pytest.raises(ValueError, match="127.0.0.1:0\n.*refused"):
          with xgb.collective.CommunicatorContext(**env):
              pass
  
file_path: xgboost/tests/python/test_tracker.py
imports: import re
  import sys
  import numpy
  import pytest
  import xgboost
  from xgboost import RabitTracker, collective
  from xgboost import testing
label_desc: Use image node_id 2 for calling a global function with example usage: test_socket_error() without return types