code: private static int unrandomize255State(int randomizedBase256Codeword,
                                            int base256CodewordPosition) {
      int pseudoRandomNumber = ((149 * base256CodewordPosition) % 255) + 1;
      int tempVariable = randomizedBase256Codeword - pseudoRandomNumber;
      return tempVariable >= 0 ? tempVariable : tempVariable + 256;
    }
docs: See ISO 16022:2006, Annex B, B.2