public void testScheduleAsync_asyncCallable_nullInsteadOfFuture() throws Exception {
    ExecutorService service = newSingleThreadScheduledExecutor();
    ListenableFuture<?> chainedFuture =
        scheduleAsync(() -> null, 1, NANOSECONDS, newSingleThreadScheduledExecutor());
    ExecutionException expected = assertThrows(ExecutionException.class, () -> chainedFuture.get());

  public void testScheduleAsync_asyncCallable_nullInsteadOfFuture() throws Exception {
    ExecutorService service = newSingleThreadScheduledExecutor();
    ListenableFuture<?> chainedFuture =
        scheduleAsync(() -> null, 1, NANOSECONDS, newSingleThreadScheduledExecutor());
    ExecutionException expected = assertThrows(ExecutionException.class, () -> chainedFuture.get());

        this.fileCache = new ConcurrentHashMap<>();
        this.lock = new ReentrantReadWriteLock();

        // Start cleanup executor for expired leases
        this.cleanupExecutor = Executors.newSingleThreadScheduledExecutor(r -> {
            Thread t = new Thread(r, "LeaseManager-Cleanup");
            t.setDaemon(true);
            return t;
        });

        // Schedule periodic cleanup

    private final Map<String, Integer> keyVersions = new ConcurrentHashMap<>();
    private final java.util.concurrent.ScheduledExecutorService rotationScheduler =
            java.util.concurrent.Executors.newSingleThreadScheduledExecutor(r -> {
                Thread t = new Thread(r, "SecureKeyManager-Rotation");
                t.setDaemon(true);
                return t;
            });

      @Override
      public Thread newThread(Runnable runnable) {
        return MoreExecutors.newThread(serviceName(), runnable);
      }
    }
    ScheduledExecutorService executor =
        Executors.newSingleThreadScheduledExecutor(new ThreadFactoryImpl());
    // Add a listener to shut down the executor after the service is stopped. This ensures that the
    // JVM shutdown will not be prevented from exiting after this service has stopped or failed.