docstr: Stops all workers (non-blocking).
docstr_tok: ["Stops","all","workers","(","non-blocking",")","."]
code: def stop(self):
      """Stops all workers (non-blocking)."""
      if self._ventilator:
          self._ventilator.stop()
      self._stop_event.set()
  
imports: import cProfile
  import pstats
  import random
  import sys
  from threading import Thread, Event
  from traceback import format_exc
  from six.moves import queue
  from petastorm.workers_pool import EmptyResultError, VentilatedItemProcessedMessage
label_desc: Use image node_id 5 for calling the ThreadPool obj's underlying member method code with example usage: obj.stop() without return types