@IgnoreJRERequirement // Users will use this only if they're already using Duration.
  public static <V extends @Nullable Object> ListenableFuture<V> withTimeout(
      ListenableFuture<V> delegate, Duration time, ScheduledExecutorService scheduledExecutor) {
    return withTimeout(delegate, toNanosSaturated(time), TimeUnit.NANOSECONDS, scheduledExecutor);
  }

  /**