code: def thread_police_duuu_daaa_duuu_daaa():
      """Attempts to stop left-over threads to avoid test interactions."""
      active_threads_before = set(threading.enumerate())
      yield
      active_threads_after = set(threading.enumerate())
  
      if XLAAccelerator.is_available():
          # Ignore the check when running XLA tests for now
          return
  
      for thread in active_threads_after - active_threads_before:
          stop = getattr(thread, "stop", None) or getattr(
              thread, "exit", None
          )
          if thread.daemon and callable(stop):
              # A daemon thread would anyway be stopped at the end of a program
              # We do it preemptively here to reduce the risk of interactions with other tests that run after
              stop()
              assert not thread.is_alive()
          elif isinstance(thread, _ChildProcessObserver):
              thread.join(timeout=10)
          elif thread.name == "QueueFeederThread":  # tensorboardX
              thread.join(timeout=20)
          elif (
              sys.version_info >= (3, 9)
              and isinstance(thread, _ExecutorManagerThread)
              or "ThreadPoolExecutor-" in thread.name
          ):
              # probably `torch.compile`, can't narrow it down further
              continue
          else:
              raise AssertionError(f"Test left zombie thread: {thread}")
  
imports: import os
  import sys
  import threading
  from typing import List
  from unittest.mock import Mock
  import lightning.fabric
  import pytest
  import torch.distributed
  from lightning.fabric.accelerators import XLAAccelerator
  from lightning.fabric.strategies.launchers.subprocess_script import _ChildProcessObserver
  from lightning.fabric.utilities.distributed import _distributed_is_initialized
label_desc: Use image node_id 4 for calling a global function with example usage: thread_police_duuu_daaa_duuu_daaa() without return types