code: public static Guid fromByteArrays(byte[]... byteArrays) throws IOException {
      if (byteArrays == null || byteArrays.length == 0) {
        throw new IOException("Attempting to compute guid for an empty array.");
      }
  
      if (byteArrays.length == 1) {
        return new Guid(byteArrays[0]);
      }
      byte[] tmp = new byte[0];
      for (byte[] arr : byteArrays) {
        tmp = ArrayUtils.addAll(tmp, arr);
      }
      return new Guid(tmp);
    }
docs: Generate a {@link Guid} for an array of byte arrays.
  @param byteArrays array of byte arrays.
  @return a single {@link Guid} for the array.
  @throws IOException