code: def tearDown(self) -> None:
      del os.environ["GLOO_DEVICE_TRANSPORT"]
      del os.environ["NCCL_SOCKET_IFNAME"]
      super().tearDown()
  
imports: import multiprocessing
  import os
  import unittest
  from typing import Callable
  from unittest import mock
  import torch.distributed
  from torch._utils_internal import TEST_MASTER_ADDR
  from torchrec.distributed.collective_utils import invoke_on_rank_and_broadcast_result, is_leader, run_on_leader
  from torchrec.test_utils import get_free_port, seed_and_log
label_desc: Use image node_id 2 for calling the CollectiveUtilsTest obj's underlying member method code with example usage: obj.tearDown() without return types