code: def test_barrier(self):
      with threading_helper.wait_threads_exit():
          self.bar = Barrier(NUMTASKS)
          self.running = NUMTASKS
          for i in range(NUMTASKS):
              thread.start_new_thread(self.task2, (i,))
          verbose_print("waiting for tasks to end")
          self.done_mutex.acquire()
          verbose_print("tasks done")
  
imports: import os
  import unittest
  import random
  from test import support
  from test.support import threading_helper
  import _thread
  import time
  import warnings
  import weakref
  from test import lock_tests
label_desc: Use image node_id 1 for calling the BarrierTest obj's underlying member method code with example usage: obj.test_barrier() without return types