code: def tearDown(self):
      self._sigterm_patcher.stop()
      self._sigint_patcher.stop()
      super().tearDown()
  
imports: import os
  import signal
  import threading
  import time
  from absl.testing import absltest
  from launchpad.launch import worker_manager
  import mock
label_desc: Use image node_id 2 for calling the WorkerManagerTest obj's underlying member method code with example usage: obj.tearDown() without return types