taskDone = false;
    Callable<Integer> task =
        new Callable<Integer>() {
          @Override
          public Integer call() {
            taskDone = true;
            return 6;
          }
        };
    Future<Integer> future =
        TestingExecutors.sameThreadScheduledExecutor().schedule(task, 10000, MILLISECONDS);
    assertTrue("Should run callable immediately", taskDone);

    taskDone = false;
    Callable<Integer> task =
        new Callable<Integer>() {
          @Override
          public Integer call() {
            taskDone = true;
            return 6;
          }
        };
    Future<Integer> future =
        TestingExecutors.sameThreadScheduledExecutor().schedule(task, 10000, MILLISECONDS);
    assertTrue("Should run callable immediately", taskDone);

  /**
   * Creates a {@code ListenableFutureTask} that will upon running, execute the given {@code
   * Callable}.
   *
   * @param callable the callable task
   * @since 10.0
   */
  public static <V extends @Nullable Object> ListenableFutureTask<V> create(Callable<V> callable) {
    return new ListenableFutureTask<>(callable);
  }

  /**
   * Creates a {@code ListenableFutureTask} that will upon running, execute the given {@code

  }

  @ParametricNullness
  private <T extends @Nullable Object> T callWithTimeout(
      Callable<T> callable, long timeoutDuration, TimeUnit timeoutUnit, boolean amInterruptible)
      throws Exception {
    checkNotNull(callable);
    checkNotNull(timeoutUnit);
    checkPositiveTimeout(timeoutDuration);

    Future<T> future = executor.submit(callable);

    try {
      return amInterruptible

Eine Python-Klasse ist also auch ein **Callable**.

Darum können Sie in **FastAPI** auch eine Python-Klasse als Abhängigkeit verwenden.

Was FastAPI tatsächlich prüft, ist, ob es sich um ein „Callable“ (Funktion, Klasse oder irgendetwas anderes) handelt und ob die Parameter definiert sind.

    CountDownLatch enterLatch = new CountDownLatch(1);
    CountDownLatch exitLatch = new CountDownLatch(1);
    TrustedListenableFutureTask<@Nullable Void> task =
        TrustedListenableFutureTask.create(
            new Callable<@Nullable Void>() {
              @Override
              public @Nullable Void call() throws Exception {
                enterLatch.countDown();
                new CountDownLatch(1).await(); // wait forever

So, a Python class is also a **callable**.

Then, in **FastAPI**, you could use a Python class as a dependency.

What FastAPI actually checks is that it is a "callable" (function, class or anything else) and the parameters defined.

   */
  @Override
  <V extends @Nullable Object> ListenableScheduledFuture<V> schedule(
      Callable<V> callable, long delay, TimeUnit unit);

  /**
   * Duration-based overload of {@link #schedule(Callable, long, TimeUnit)}.
   *
   * @since 29.0
   */
  @J2ktIncompatible
  default <V extends @Nullable Object> ListenableScheduledFuture<V> schedule(
      Callable<V> callable, Duration delay) {

    List<Callable<T>> tasks = ImmutableList.of();
    List<? extends Future<?>> unused = executor.invokeAll(tasks);
  }

  public void testListeningDecorator() throws Exception {
    ListeningExecutorService service = listeningDecorator(newDirectExecutorService());
    assertSame(service, listeningDecorator(service));
    List<Callable<String>> callables = ImmutableList.of(Callables.returning("x"));

                    runnableThrowing(exception), DELAY_MS, MILLISECONDS));
    assertThat(e).hasCauseThat().isEqualTo(exception);
  }

  public static <T> Callable<T> callableThrowing(Exception exception) {
    return new Callable<T>() {
      @Override
      public T call() throws Exception {
        throw exception;
      }
    };
  }