code: def test_run_async(self):
      counter = mp.Value("l", 0)
  
      def run_func(process_idx):
          for _ in range(1000):
              with counter.get_lock():
                  counter.value += 1
  
      async_.run_async(4, run_func)
      self.assertEqual(counter.value, 4000)
  
imports: import multiprocessing
  import os
  import signal
  import sys
  import unittest
  import warnings
  import chainer
  import chainer.links
  from chainer import optimizers
  import copy
  import numpy
  import chainerrl
  from chainerrl.misc import async_
label_desc: Use image node_id 8 for calling the TestAsync obj's underlying member method code with example usage: obj.test_run_async() without return types