def METHOD_NAME():
    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