code: def test_process_worker_failure(self):
      self._manager.process_worker("failure", ["cat", "missing_file"])
      with self.assertRaisesRegexp(
          RuntimeError, "One of the workers exited"
      ):
          self._manager.wait()
  
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 13 for calling the WorkerManagerTest obj's underlying member method code with example usage: obj.test_process_worker_failure() without return types