}
        int byte2 = bytes[index++];
        if (byte2 > (byte) 0xBF
            // Overlong? 5 most significant bits must not all be zero.
            || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
            // Check for illegal surrogate codepoints.
            || (byte1 == (byte) 0xED && byte2 >= (byte) 0xA0)
            // Third byte trailing-byte test.
            || bytes[index++] > (byte) 0xBF) {
          return false;

  }

  /** Convenience method to compute a fingerprint on a full bytes array. */
  private static long fingerprint(byte[] bytes) {
    return fingerprint(bytes, bytes.length);
  }

  /** Convenience method to compute a fingerprint on a subset of a byte array. */
  private static long fingerprint(byte[] bytes, int length) {
    return HASH_FN.hashBytes(bytes, 0, length).asLong();
  }

  /**

  public void testBytes() {
    Sink sink = new Sink(4); // byte order insignificant here
    byte[] expected = {1, 2, 3, 4, 5, 6, 7, 8};
    sink.putByte((byte) 1);
    sink.putBytes(new byte[] {2, 3, 4, 5, 6});
    sink.putByte((byte) 7);
    sink.putBytes(new byte[] {});
    sink.putBytes(new byte[] {8});
    HashCode unused = sink.hash();
    sink.assertInvariants(8);
    sink.assertBytes(expected);

        // Compare the bytes. Note that the file stores UTF-8 encoded bytes, so we must compare the
        // unsigned bytes.
        var compareResult: Int
        var currentLabelIndex = labelIndex
        var currentLabelByteIndex = 0
        var publicSuffixByteIndex = 0

        var expectDot = false
        while (true) {
          val byte0: Int
          if (expectDot) {

    // Write the tagClass, tag, and constructed bit. This takes 1 byte if tag is less than 31.
    if (tag < 31) {
      val byte0 = tagClass or constructedBit or tag.toInt()
      sink.writeByte(byte0)
    } else {
      val byte0 = tagClass or constructedBit or 0b0001_1111
      sink.writeByte(byte0)
      writeVariableLengthLong(tag)
    }

    // Write the length. This takes 1 byte if length is less than 128.
    val length = content.size

    // loop we keep 56 bytes of state: v, w, x, y, and z.
    long x = load64(bytes, offset);
    long y = load64(bytes, offset + length - 16) ^ K1;
    long z = load64(bytes, offset + length - 56) ^ K0;
    long[] v = new long[2];
    long[] w = new long[2];
    weakHashLength32WithSeeds(bytes, offset + length - 64, length, y, v);

   * {@code bytes[off + len - 1]} is the last.
   *
   * @param bytes a byte array
   * @param off the start offset in the array
   * @param len the number of bytes to write
   * @return this instance
   * @throws IndexOutOfBoundsException if {@code off < 0} or {@code off + len > bytes.length} or
   *     {@code len < 0}
   */
  @CanIgnoreReturnValue

        }
    }

    /**
     * Reads the contents of the file channel into a byte buffer.
     *
     * @param channel
     *            The file channel. Must not be {@literal null}.
     * @param buffer
     *            The byte buffer. Must not be {@literal null}.
     * @return The number of bytes read.
     */
    public static int read(final FileChannel channel, final ByteBuffer buffer) {

  internal const val OPCODE_FLAG_CONTROL = 8

  /**
   * Byte 1 flag for whether the payload data is masked.
   *
   * If this flag is set, the next four
   * bytes represent the mask key. These bytes appear after any additional bytes specified by [B1_MASK_LENGTH].
   */
  internal const val B1_FLAG_MASK = 128

  /**
   * Byte 1 mask for the payload length.
   *
   * If this value is [PAYLOAD_SHORT], the next two

    // loop we keep 56 bytes of state: v, w, x, y, and z.
    long x = load64(bytes, offset);
    long y = load64(bytes, offset + length - 16) ^ K1;
    long z = load64(bytes, offset + length - 56) ^ K0;
    long[] v = new long[2];
    long[] w = new long[2];
    weakHashLength32WithSeeds(bytes, offset + length - 64, length, y, v);