code: function respondWithCode(res, code, message) {
              /* eslint-disable */
              res._headers = {};
              res._headerNames = {};
              res.statusCode = code;
              /* eslint-enable */
              res.setHeader('Content-Type', 'text/plain; charset=UTF-8');
              res.setHeader('Content-Length', Buffer.byteLength(message));
              res.setHeader('X-Content-Type-Options', 'nosniff');
              res.end(message);
          }
docs: Responds with HTTP status code and a message.
  
  @param {Object} res     - response object
  @param {number} code    - http response code
  @param {string} message - message