*
   * @throws NumberFormatException if the string does not contain a parsable unsigned {@code long}
   *     value, or {@code radix} is not between {@link Character#MIN_RADIX} and {@link
   *     Character#MAX_RADIX}
   */
  @CanIgnoreReturnValue
  public static UnsignedLong valueOf(String string, int radix) {
    return fromLongBits(UnsignedLongs.parseUnsignedLong(string, radix));
  }

  /**

    }
  }

  @J2ktIncompatible
  @GwtIncompatible // too slow
  public void testToStringRadix() {
    for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
      for (int l : TEST_INTS) {
        UnsignedInteger value = UnsignedInteger.fromIntBits(l);
        assertThat(value.toString(radix)).isEqualTo(value.bigIntegerValue().toString(radix));
      }
    }

    return toString(10);
  }

  /**
   * Returns a string representation of the {@code UnsignedInteger} value, in base {@code radix}. If
   * {@code radix < Character.MIN_RADIX} or {@code radix > Character.MAX_RADIX}, the radix {@code
   * 10} is used.
   */
  public String toString(int radix) {
    return UnsignedInts.toString(value, radix);
  }