code: def setUp(self):
      self.test_dir = tempfile.mkdtemp()
  
      # remove any lingering environment variables
      for env in os.environ.keys():
          if env.startswith("PET_"):
              del os.environ[env]
  
      # set a sentinel env var on the parent proc
      # this should be present on the child and gets
      # asserted in ``bin/test_script.py``
      os.environ["TEST_SENTINEL_PARENT"] = "FOOBAR"
  
imports: import multiprocessing
  import os
  import runpy
  import shutil
  import subprocess
  import sys
  import tempfile
  import unittest
  import uuid
  from contextlib import closing
  from unittest import mock
  from unittest.mock import Mock, patch
  import torch.distributed.run
  from torch.distributed.elastic.agent.server.api import RunResult, WorkerState
  from torch.distributed.elastic.multiprocessing.errors import ChildFailedError
  from torch.distributed.elastic.rendezvous.etcd_server import EtcdServer
  from torch.distributed.elastic.utils import get_socket_with_port
  from torch.distributed.elastic.utils.distributed import get_free_port
  from torch.testing._internal.common_utils import TEST_WITH_DEV_DBG_ASAN, skip_but_pass_in_sandcastle_if
label_desc: Use image node_id 3 for calling the ElasticLaunchTest obj's underlying member method code with example usage: obj.setUp() without return types