AbstractService service, ScheduledExecutorService executor, Runnable task) {
          return new FutureAsCancellable(
              executor.scheduleWithFixedDelay(task, initialDelay, delay, unit));
        }
      };
    }

    /**
     * Returns a {@link Scheduler} that schedules the task using the {@link
     * ScheduledExecutorService#scheduleAtFixedRate} method.
     *

    return delegate().submit(task);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    return delegate().submit(task);
  }

  @Override
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Runnable task, @ParametricNullness T result) {
    return delegate().submit(task, result);
  }

## Create a task function { #create-a-task-function }

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

    protected CommonPoolUtil() {
        // nothing
    }

    /**
     * Executes the given task in the common ForkJoinPool.
     *
     * @param task
     *            the task to execute
     */
    public static void execute(final Runnable task) {
        ForkJoinPool.commonPool().execute(() -> {
            final Thread currentThread = Thread.currentThread();

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    return (ListenableFuture<?>) super.submit(task);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this
  @Override
  public <T extends @Nullable Object> ListenableFuture<T> submit(
      Runnable task, @ParametricNullness T result) {
    return (ListenableFuture<T>) super.submit(task, result);
  }

      "FINE: Q10000 scheduled after 100 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
      "FINE: Q10000 run again after  50 µs: task",
      "FINE: Q10000 starting              : task",
      "FINE: Q10000 finished run in   0 µs: task",
      "FINE: Q10000 run again after 150 µs: task",
      "FINE: Q10000 starting              : task",

  /** The task that's currently executing. Guarded by `this`. */
  private var currentTask: SerialTask = TestThreadSerialTask

  /** The coordinator task if it's waiting, and how it will resume. Guarded by `this`. */
  private var waitingCoordinatorTask: SerialTask? = null
  private var waitingCoordinatorInterrupted = false
  private var waitingCoordinatorNotified = false

        FutureTask<ProjectSegment> projectBuildFutureTask = new FutureTask<>(task);
        projectBuildFutureTasks.add(projectBuildFutureTask);
        if (finishImmediately) {
            projectBuildFutureTask.run();
        }
        return projectBuildFutureTask;
    }

    @Override
    public Future<ProjectSegment> submit(Runnable task, ProjectSegment result) {

    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Start the task to put it in the RUNNING state.  Have to use a separate
    // thread because the task will block on the task latch after unblocking
    // the run latch.
    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    TrustedListenableFutureTask<Integer> task = TrustedListenableFutureTask.create(returning(2));
    assertFalse(task.isDone());
    task.run();
    assertTrue(task.isDone());
    assertFalse(task.isCancelled());
    assertEquals(2, getDone(task).intValue());
  }

  public void testCancelled() throws Exception {
    TrustedListenableFutureTask<Integer> task = TrustedListenableFutureTask.create(returning(2));