}

  private static String unsafeComparatorClassName() {
    return UnsignedBytes.LexicographicalComparatorHolder.class.getName() + "$UnsafeComparator";
  }

  private static boolean unsafeComparatorAvailable() {
    // See Java Puzzler #44
    // Use reflection instead of catching NoClassDefFoundError
    try {
      Class.forName(unsafeComparatorClassName());
      return true;