docs: @Override
    public String digestParams(RestInvocation restInvocation) {
  
      Params params = restInvocation.getParamsMap().get(FormParam.class);
      Map<String, String> nameValues = params.asHttpHeaders();
      nameValues.remove("signature");
  
      Params newParams = Params.of();
      for (Map.Entry<String, String> nameValue : nameValues.entrySet()) {
        newParams.add(nameValue.getKey(), nameValue.getValue());
      }
  
      String message = newParams.asQueryString();
  
      Mac mac = getMac();
      mac.update(message.getBytes());
  
      return String.format("%064x", new BigInteger(1, mac.doFinal()));
    }