char c3 = input.charAt(i + 3);
          if (c0 < 0x80 && c1 < 0x80 && c2 < 0x80 && c3 < 0x80) {
            update(4, c0 | (c1 << 8) | (c2 << 16) | (c3 << 24));
            i += 4;
          } else {
            break;
          }
        }

        for (; i < utf16Length; i++) {
          char c = input.charAt(i);
          if (c < 0x80) {
            update(1, c);
          } else if (c < 0x800) {

          when {
            b == 0x80 -> {
              // 10000000
              throw IOException("index == 0")
            }

            b and 0x80 == 0x80 -> {
              // 1NNNNNNN
              val index = readInt(b, PREFIX_7_BITS)
              readIndexedHeader(index - 1)
            }

            b == 0x40 -> {
              // 01000000

        sink.writeByte(ranges[rangesIndex + 2].code)
        sink.writeByte(ranges[rangesIndex + 3].code or 0x80)
      }

      127 -> {
        // Mapped inline to the sequence: [b2a, b3a].
        sink.writeByte(ranges[rangesIndex + 2].code or 0x80)
        sink.writeByte(ranges[rangesIndex + 3].code or 0x80)
      }

      else -> {
        error("unexpected rangesIndex for $codePoint")
      }
    }

	for _, c := range s {
		if c >= 0x80 || c == 0x00 {
			return false
		}
	}
	return true
}

// toASCII converts the input to an ASCII C-style string.
// This is a best effort conversion, so invalid characters are dropped.
func toASCII(s string) string {
	if isASCII(s) {
		return s
	}
	b := make([]byte, 0, len(s))
	for _, c := range s {
		if c < 0x80 && c != 0x00 {
			b = append(b, byte(c))
		}
	}

  public void testCollisionsDueToIncorrectSignExtension() {
    byte[] col1 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x80};
    byte[] col2 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x81};
    byte[] col3 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0xff};

    ImmutableSet<HashCode> hashCodes =
        ImmutableSet.of(

  public void testCollisionsDueToIncorrectSignExtension() {
    byte[] col1 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x80};
    byte[] col2 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0x81};
    byte[] col3 = new byte[] {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, (byte) 0xff};

    ImmutableSet<HashCode> hashCodes =
        ImmutableSet.of(

0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97,...

  private UnsignedBytes() {}

  /**
   * The largest power of two that can be represented as an unsigned {@code byte}.
   *
   * @since 10.0
   */
  public static final byte MAX_POWER_OF_TWO = (byte) 0x80;

  /**
   * The largest value that fits into an unsigned byte.
   *
   * @since 13.0
   */
  public static final byte MAX_VALUE = (byte) 0xFF;

  private static final int UNSIGNED_MASK = 0xFF;

  /**

          current.sourceCodePoint0,
          current.section + 0x7f,
          current.type,
          current.mappedTo,
        )
      current =
        Mapping(
          current.section + 0x80,
          current.sourceCodePoint1,
          current.type,
          current.mappedTo,
        )
    } else {
      result += current
      current = if (i.hasNext()) i.next() else break
    }
  }

  private const val BASE = 36
  private const val TMIN = 1
  private const val TMAX = 26
  private const val SKEW = 38
  private const val DAMP = 700
  private const val INITIAL_BIAS = 72
  private const val INITIAL_N = 0x80

  /**
   * Returns null if any label is oversized so much that the encoder cannot encode it without
   * integer overflow. This will not return null for labels that fit within the DNS size
   * limits.
   */