code: def undo(fn):
      try:
          yield
      finally:
          fn()
  
imports: import contextlib
  import multiprocessing
  import os
  import shutil
  import sys
  import tempfile
  import time
  import traceback
  import cloudpickle
  import mock
  from horovod.runner.util.threads import in_thread
label_desc: Use image node_id 9 for calling a global function with example usage: undo(fn) without return types