code: function() {
          return function (req, res, next) {
  
              if (!req.locals) {
                  req.locals = {};
              }
              var requestTemplates = getTemplates(res);
              req.locals.templates = requestTemplates;
              req.locals.knownTemplates = knownTemplates;
              if (!res.locals) {
                  res.locals = {};
              }
              res.locals.templates = requestTemplates;
              res.locals.knownTemplates = knownTemplates;
              res.locals.renderTemplate = invokeRenderTemplate.bind(null, res.locals);
  
              return next();
          };
      }
docs: Attaches the 'templates' property to 'locals' pf request and response objects. if no 'locals' found, it is created on demand.
  @param req {IncomingMessage}
  @param res {ServerResponse}
  @param next {Function}
  @returns {function} configured middleware function
  @api public