*/
    return ref == null ? Optional.absent() : Optional.fromNullable(enumClass.cast(ref.get()));
  }

  static String formatCompact4Digits(double value) {
    return String.format(Locale.ROOT, "%.4g", value);
  }

  static boolean stringIsNullOrEmpty(@CheckForNull String string) {
    return string == null || string.isEmpty();
  }

  /**
   * Returns the string if it is not null, or an empty string otherwise.

    return ref == null ? Optional.<T>absent() : Optional.of(enumClass.cast(ref.get()));
  }

  static String formatCompact4Digits(double value) {
    return String.format(Locale.ROOT, "%.4g", value);
  }

  static boolean stringIsNullOrEmpty(@CheckForNull String string) {
    return string == null || string.isEmpty();
  }

  /**
   * Returns the string if it is not null, or an empty string otherwise.