docs: private static byte[] getAuthenticationCode(byte[] secret, byte[] data, int length) {
      try {
        SecretKey secretKey = new SecretKeySpec(secret, MAC_ALGORITHM);
        Mac mac = Mac.getInstance(MAC_ALGORITHM);
        mac.init(secretKey);
        mac.update(data, 0, length);
        return mac.doFinal();
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }