* @throws IllegalArgumentException if {@code radix} is not between {@link Character#MIN_RADIX}
   *     and {@link Character#MAX_RADIX}.
   */
  public static String toString(long x, int radix) {
    checkArgument(
        radix >= Character.MIN_RADIX && radix <= Character.MAX_RADIX,
        "radix (%s) must be between Character.MIN_RADIX and Character.MAX_RADIX",
        radix);
    if (x == 0) {
      // Simply return "0"

  }

  public void testParseLongThrowsExceptionForInvalidRadix() {
    // Valid radix values are Character.MIN_RADIX to Character.MAX_RADIX, inclusive.
    assertThrows(
        NumberFormatException.class,
        () -> UnsignedLongs.parseUnsignedLong("0", Character.MIN_RADIX - 1));

    assertThrows(
        NumberFormatException.class,

  private static void tryParseAndAssertEquals(Integer expected, String value) {
    assertThat(Ints.tryParse(value)).isEqualTo(expected);
  }

  public void testTryParse_radix() {
    for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
      radixEncodeParseAndAssertEquals(0, radix);
      radixEncodeParseAndAssertEquals(8000, radix);
      radixEncodeParseAndAssertEquals(-8000, 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);

  @Override
  public String toString() {
    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);
  }

   */
  private static void tryParseAndAssertEquals(Long expected, String value) {
    assertThat(Longs.tryParse(value)).isEqualTo(expected);
  }

  public void testTryParse_radix() {
    for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
      radixEncodeParseAndAssertEquals(0L, radix);
      radixEncodeParseAndAssertEquals(8000L, radix);
      radixEncodeParseAndAssertEquals(-8000L, radix);

  private static void tryParseAndAssertEquals(Integer expected, String value) {
    assertThat(Ints.tryParse(value)).isEqualTo(expected);
  }

  public void testTryParse_radix() {
    for (int radix = Character.MIN_RADIX; radix <= Character.MAX_RADIX; radix++) {
      radixEncodeParseAndAssertEquals(0, radix);
      radixEncodeParseAndAssertEquals(8000, radix);
      radixEncodeParseAndAssertEquals(-8000, radix);

   *     {@code string} has a length of zero or cannot be parsed as an integer value
   * @throws IllegalArgumentException if {@code radix < Character.MIN_RADIX} or {@code radix >
   *     Character.MAX_RADIX}
   * @throws NullPointerException if {@code string} is {@code null}
   * @since 19.0
   */
  public static @Nullable Integer tryParse(String string, int radix) {