@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) {

      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

  }

  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

 *   <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}.

    assertThrows(IllegalStateException.class, builder2::weakValues);
  }

  @J2ktIncompatible
  @GwtIncompatible // Duration
  @IgnoreJRERequirement // No more dangerous than wherever the caller got the Duration from
  public void testLargeDurationsAreOk() {
    Duration threeHundredYears = Duration.ofDays(365 * 300);
    CacheBuilder<Object, Object> unused =
        CacheBuilder.newBuilder()

    assertThrows(IllegalStateException.class, builder2::weakValues);
  }

  @J2ktIncompatible
  @GwtIncompatible // Duration
  public void testLargeDurationsAreOk() {
    Duration threeHundredYears = Duration.ofDays(365 * 300);
    CacheBuilder<Object, Object> unused =
        CacheBuilder.newBuilder()
            .expireAfterWrite(threeHundredYears)

        } catch (Exception e) {
            // Expected
        }
        long duration = System.currentTimeMillis() - startTime;

        // Test should complete in under 1 second (much less than the original 25+ seconds)
        assertTrue("Test should complete quickly (duration: " + duration + "ms)", duration < 1000);
    }

    // Fast mock implementations to minimize overhead