// meaning that a string will be truncated to just the truncation indicator itself
    checkArgument(
        truncationLength >= 0,
        "maxLength (%s) must be >= length of the truncation indicator (%s)",
        maxLength,
        truncationIndicator.length());

    if (seq.length() <= maxLength) {
      String string = seq.toString();

    this.toString = checkNotNull(toString);
    this.prototype = getMessageDigest(algorithmName);
    int maxLength = prototype.getDigestLength();
    checkArgument(
        bytes >= 4 && bytes <= maxLength, "bytes (%s) must be >= 4 and < %s", bytes, maxLength);
    this.bytes = bytes;
    this.supportsClone = supportsClone(prototype);
  }

  private static boolean supportsClone(MessageDigest digest) {

   * @param offset the start offset in the data
   * @param maxLength the maximum number of bytes to write
   * @return the number of bytes written to {@code dest}
   * @throws IndexOutOfBoundsException if there is not enough room in {@code dest}
   */
  @CanIgnoreReturnValue
  public int writeBytesTo(byte[] dest, int offset, int maxLength) {
    maxLength = Ints.min(maxLength, bits() / 8);

    // meaning that a string will be truncated to just the truncation indicator itself
    checkArgument(
        truncationLength >= 0,
        "maxLength (%s) must be >= length of the truncation indicator (%s)",
        maxLength,
        truncationIndicator.length());

    if (seq.length() <= maxLength) {
      String string = seq.toString();

      checkArgument(length >= 0, "length (%s) may not be negative", length);
      long maxLength = this.length - offset;
      return maxLength <= 0
          ? ByteSource.empty()
          : ByteSource.this.slice(this.offset + offset, Math.min(length, maxLength));
    }

    @Override
    public boolean isEmpty() throws IOException {
      return length == 0 || super.isEmpty();