code: public void okResponse(String responseCode, String message) {
          untagged();
          message(OK);
          responseCode(responseCode);
          message(message);
          end();
      }
docs: Writes an untagged OK response, with the supplied response code,
  and an optional message.
  
  @param responseCode The response code, included in [].
  @param message      The message to follow the []