code: def test_ventilator_processes(self):
      self._test_simple_ventilation(lambda: ProcessPool(10))
  
imports: import time
  import unittest
  from petastorm.workers_pool import EmptyResultError
  from petastorm.workers_pool.dummy_pool import DummyPool
  from petastorm.workers_pool.process_pool import ProcessPool
  from petastorm.workers_pool.tests.stub_workers import IdentityWorker
  from petastorm.workers_pool.thread_pool import ThreadPool
  from petastorm.workers_pool.ventilator import ConcurrentVentilator
label_desc: Use image node_id 2 for calling the TestWorkersPool obj's underlying member method code with example usage: obj.test_ventilator_processes() without return types