docs: static boolean checkStandardUPCEANChecksum(CharSequence s) throws FormatException {
      int length = s.length();
      if (length == 0) {
        return false;
      }
      int check = Character.digit(s.charAt(length - 1), 10);
      return getStandardUPCEANChecksum(s.subSequence(0, length - 1)) == check;
    }