code: function echo(req, res) {
      // TODO: headers... and so on...
      return res.json({
          method: req.method,
          path: req.baseUrl + req.path,
          query: req.query,
          body: req.body
      });
  }
docs: simple echo route(http request handler) to easy test.
  
  @param {express.request} req
  @param {express.response} res