@GwtIncompatible // Duration
  @SuppressWarnings("GoodTime") // duration decomposition
  private static long toNanosSaturated(Duration duration) {
    // Using a try/catch seems lazy, but the catch block will rarely get invoked (except for
    // durations longer than approximately +/- 292 years).
    try {
      return duration.toNanos();
    } catch (ArithmeticException tooBig) {

  }

  static class DurationSpec {
    private final long duration;
    private final TimeUnit unit;

    private DurationSpec(long duration, TimeUnit unit) {
      this.duration = duration;
      this.unit = unit;
    }

    public static DurationSpec of(long duration, TimeUnit unit) {
      return new DurationSpec(duration, unit);
    }

    @Override
    public int hashCode() {

  @GwtIncompatible // Duration
  @SuppressWarnings("GoodTime") // Duration decomposition
  @IgnoreJRERequirement // No more dangerous than wherever the caller got the Duration from
  private static long toNanosSaturated(Duration duration) {
    // Using a try/catch seems lazy, but the catch block will rarely get invoked (except for
    // durations longer than approximately +/- 292 years).
    try {
      return duration.toNanos();

      Supplier<T> delegate, Duration duration) {
    checkNotNull(delegate);
    // The alternative of `duration.compareTo(Duration.ZERO) > 0` causes J2ObjC trouble.
    checkArgument(
        !duration.isNegative() && !duration.isZero(), "duration (%s) must be > 0", duration);
    return new ExpiringMemoizingSupplier<>(delegate, toNanosSaturated(duration));
  }

  @VisibleForTesting

            before = time.time()
            response: Response = await original_route_handler(request)
            duration = time.time() - before
            response.headers["X-Response-Time"] = str(duration)
            print(f"route duration: {duration}")
            print(f"route response: {response}")
            print(f"route response headers: {response.headers}")
            return response

   */
  @CanIgnoreReturnValue
  @J2ktIncompatible
  @GwtIncompatible // java.time.Duration
  @ParametricNullness
  @IgnoreJRERequirement // Users will use this only if they're already using Duration.
  public static <V extends @Nullable Object> V getUninterruptibly(
      Future<V> future, Duration timeout) throws ExecutionException, TimeoutException {

 *   <li>{@code maximumWeight=[long]}: sets {@link CacheBuilder#maximumWeight}.
 *   <li>{@code expireAfterAccess=[duration]}: sets {@link CacheBuilder#expireAfterAccess}.
 *   <li>{@code expireAfterWrite=[duration]}: sets {@link CacheBuilder#expireAfterWrite}.
 *   <li>{@code refreshAfterWrite=[duration]}: sets {@link CacheBuilder#refreshAfterWrite}.
 *   <li>{@code weakKeys}: sets {@link CacheBuilder#weakKeys}.

 *   <li>{@code maximumWeight=[long]}: sets {@link CacheBuilder#maximumWeight}.
 *   <li>{@code expireAfterAccess=[duration]}: sets {@link CacheBuilder#expireAfterAccess}.
 *   <li>{@code expireAfterWrite=[duration]}: sets {@link CacheBuilder#expireAfterWrite}.
 *   <li>{@code refreshAfterWrite=[duration]}: sets {@link CacheBuilder#refreshAfterWrite}.
 *   <li>{@code weakKeys}: sets {@link CacheBuilder#weakKeys}.

internal fun checkDuration(
  name: String,
  duration: Long,
  unit: TimeUnit,
): Int {
  check(duration >= 0L) { "$name < 0" }
  val millis = unit.toMillis(duration)
  require(millis <= Integer.MAX_VALUE) { "$name too large" }
  require(millis != 0L || duration <= 0L) { "$name too small" }
  return millis.toInt()
}

internal fun checkDuration(
  name: String,
  duration: Duration,
): Int {

     *
     * The default value is 0 which imposes no timeout.
     */
    @Suppress("NewApi")
    @IgnoreJRERequirement
    fun callTimeout(duration: Duration) =
      apply {
        callTimeout(duration.toMillis(), MILLISECONDS)
      }

    /**
     * Sets the default timeout for complete calls. A value of 0 means no timeout, otherwise values