docs: static byte[] hmacSha1(StringBuilder message, String key) {
      try {
        Mac mac = Mac.getInstance("HmacSHA1");
        mac.init(new SecretKeySpec(key.getBytes(), "HmacSHA1"));
        return mac.doFinal(message.toString().getBytes());
      } catch (Exception e) {
        throw new RuntimeException(e);
      }
    }