code: def test_shutdown_nowait(client):
      # shutdown(wait=False) cancels pending tasks
      e = client.get_executor()
      start = time()
      fut = e.submit(sleep, 5.0)
      e.shutdown(wait=False)
      assert time() < start + 2.0
      sleep(0.1)  # wait for future outcome to propagate
      assert fut.cancelled()
  
      with pytest.raises(RuntimeError):
          e.submit(sleep, 1.0)
  
imports: from __future__ import annotations
  import random
  from concurrent.futures import FIRST_COMPLETED, FIRST_EXCEPTION, Future, TimeoutError, as_completed, wait
  from time import sleep
  import pytest
  from tlz import take
  from distributed.event import Event
  from distributed.metrics import time
  from distributed.utils import CancelledError
  from distributed.utils_test import inc, slowadd, slowinc, throws, varying
label_desc: Use image node_id 15 for calling a global function with example usage: test_shutdown_nowait(client) without return types