spec.recordStats = true;
    }
  }

  /** Base class for parsing times with durations */
  private abstract static class DurationParser implements ValueParser {
    abstract void parseDuration(CacheBuilderSpec spec, long duration, TimeUnit unit);

    @Override
    public void parse(CacheBuilderSpec spec, String key, @Nullable String value) {
      if (isNullOrEmpty(value)) {

      spec.recordStats = true;
    }
  }

  /** Base class for parsing times with durations */
  private abstract static class DurationParser implements ValueParser {
    abstract void parseDuration(CacheBuilderSpec spec, long duration, TimeUnit unit);

    @Override
    public void parse(CacheBuilderSpec spec, String key, @Nullable String value) {
      if (isNullOrEmpty(value)) {

	if e != nil {
		return psv, ErrMalformedPresignedDate
	}

	// Save expires in native time.Duration.
	preSignV4Values.Expires, e = time.ParseDuration(query.Get(xhttp.AmzExpires) + "s")
	if e != nil {
		return psv, ErrMalformedExpires
	}

	if preSignV4Values.Expires < 0 {
		return psv, ErrNegativeExpires
	}