*
   * <p><b>Java 8+ users:</b> use {@link Long#parseUnsignedLong(String)} instead.
   *
   * @throws NumberFormatException if the string does not contain a valid unsigned {@code long}
   *     value
   * @throws NullPointerException if {@code string} is null (in contrast to {@link
   *     Long#parseLong(String)})
   */
  @CanIgnoreReturnValue
  public static long parseUnsignedLong(String string) {

   *     Character#MAX_RADIX}
   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(String string, int radix) {
    return fromLongBits(UnsignedLongs.parseUnsignedLong(string, radix));
  }

  /**
   * Returns the result of adding this and {@code val}. If the result would have more than 64 bits,
   * returns the low 64 bits of the result.
   *
   * @since 14.0
   */