* identify deadlocks.
   */
  @VisibleForTesting
  static final class Blocker extends AbstractOwnableSynchronizer implements Runnable {
    private final InterruptibleTask<?> task;

    private Blocker(InterruptibleTask<?> task) {
      this.task = task;
    }

    @Override
    public void run() {}

    private void setOwner(Thread thread) {
      super.setExclusiveOwnerThread(thread);
    }

	select {
	case globalBackgroundHealRoutine.tasks <- task:
		if serverDebugLog {
			fmt.Printf("Task in the queue: %#v\n", task)
		}
	case <-h.ctx.Done():
		return nil
	}

	// task queued, now wait for the response.
	select {
	case res := <-task.respCh:
		if !h.reportProgress {
			if errors.Is(res.err, errSkipFile) { // this is only sent usually by nopHeal
				return nil
			}

  ASSERT_EQ(TF_GetCode(status.get()), TF_OK) << TF_Message(status.get());

  const char* device_name = "/job:localhost/replica:0/task:0/device:CUSTOM:0";
  const char* first_device_name =
      "/job:localhost/replica:0/task:0/device:CPU:0";
  const char* second_device_name =
      "/job:localhost/replica:0/task:0/device:CPU:1";
  std::array<const char*, 2> underlying_devices{first_device_name,

            "--continue",
            "--no-watch-fs"
        ).buildAndFail()
        assertEquals(TaskOutcome.SUCCESS, result.task(":successful-report:test")!!.outcome)
        assertEquals(TaskOutcome.FAILED, result.task(":failed-report-with-leftover:test")!!.outcome)
        assertEquals(TaskOutcome.FAILED, result.task(":failed-test-with-leftover:test")!!.outcome)

  // 3. Replace worker1 with a new worker in server_def_0 and server_def_1.
  ReplaceTaskInServerDef(&server_def_0, /*task_index=*/1, "localhost", port);
  ReplaceTaskInServerDef(&server_def_1, /*task_index=*/1, "localhost", port);
  // 4. Start a new task to replace worker1.
  server_def_0.set_task_index(1);
  worker_server1.release();
  ASSERT_TRUE(tensorflow::GrpcServer::Create(

    return;
  }
  std::vector<tensorflow::CoordinatedTask> task_vec(tasks.length);
  auto* task_iter = static_cast<const tensorflow::CoordinatedTask*>(tasks.data);
  for (size_t i = 0; i < tasks.length; ++i) {
    task_vec[i].set_job_name(task_iter->job_name());
    task_vec[i].set_task_id(task_iter->task_id());
    ++task_iter;
  }
  auto results = coord_agent->GetTaskState(task_vec);
  if (!results.ok()) {

          throw new TimeoutException("Timeout waiting for task.");
        }

        return getValue();
      }

      /**
       * Blocks until {@link #complete(Object, Throwable, int)} has been successfully called. Throws
       * a {@link CancellationException} if the task was cancelled, or a {@link ExecutionException}
       * if the task completed with an error.
       */

          throw new TimeoutException("Timeout waiting for task.");
        }

        return getValue();
      }

      /**
       * Blocks until {@link #complete(Object, Throwable, int)} has been successfully called. Throws
       * a {@link CancellationException} if the task was cancelled, or a {@link ExecutionException}
       * if the task completed with an error.
       */

    ExecutorService delegate = mock(ExecutorService.class);
    ListeningExecutorService service = listeningDecorator(delegate);
    Runnable task =
        new Runnable() {
          @Override
          public void run() {}
        };
    service.execute(task);
    verify(delegate).execute(task);
  }

  public void testListeningDecorator_scheduleSuccess() throws Exception {

  ASSERT_TRUE(TF_GetCode(status.get()) == TF_OK) << TF_Message(status.get());

  std::vector<std::string> devices{
      "/job:localhost/replica:0/task:0/device:CPU:0",
      "/job:localhost/replica:0/task:0/device:CPU:1"};
  ParallelDevice parallel_device(std::move(devices));
  std::unique_ptr<TFE_Op, decltype(&TFE_DeleteOp)> handle_op(