type Config struct {
	ReplicationWorkersWait time.Duration `json:"replicationWorkersWait"`
	KeyRotationWorkersWait time.Duration `json:"keyRotationWorkersWait"`
	ExpirationWorkersWait  time.Duration `json:"expirationWorkersWait"`
}

// ExpirationWait returns the duration for which a batch expiration worker
// would wait before working on next object.
func (opts Config) ExpirationWait() time.Duration {
	configMu.RLock()
	defer configMu.RUnlock()

  }

  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() {

  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) {
      return duration.isNegative() ? Long.MIN_VALUE : Long.MAX_VALUE;
    }
  }

  private Internal() {}

  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) {
      return duration.isNegative() ? Long.MIN_VALUE : Long.MAX_VALUE;
    }
  }

  private Internal() {}

  @SuppressWarnings("GoodTime") // duration decomposition
  private static long toNanosSaturated(java.time.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() {

		{[]string{"unknown-host:65432"}, time.Duration(0), time.Duration(0), time.Duration(0), []bool{true}},                            // 4
		{[]string{"localhost:65432"}, time.Duration(0), time.Duration(0), time.Duration(0), []bool{false}},                              // 5

    String result = executorService.invokeAny(tasks, Duration.ofSeconds(7));

    assertThat(result).isEqualTo("invokeAny");
    assertThat(recordedTasks).isSameInstanceAs(tasks);
    assertThat(recordedTimeUnit).isEqualTo(NANOSECONDS);
    assertThat(Duration.ofNanos(recordedTimeout)).isEqualTo(Duration.ofSeconds(7));
  }

  public void testInvokeAll() throws Exception {

    }
  }

  @GwtIncompatible // java.time.Duration
  public void testTimeToLive_setTwice_duration() {
    CacheBuilder<Object, Object> builder =
        CacheBuilder.newBuilder().expireAfterWrite(java.time.Duration.ofSeconds(3600));
    assertThrows(
        IllegalStateException.class,
        () -> builder.expireAfterWrite(java.time.Duration.ofSeconds(3600)));
  }

  public void testTimeToIdle_negative() {

    return this;
  }

  /**
   * Advances the ticker value by {@code duration}.
   *
   * @since 28.0
   */
  @GwtIncompatible
  @J2ktIncompatible
  @CanIgnoreReturnValue
  @SuppressWarnings("Java7ApiChecker") // guava-android can rely on library desugaring now.
  public FakeTicker advance(Duration duration) {
    return advance(duration.toNanos());
  }

  /**