docs: function done() {
      // get the next route from the stack
      route = stack.pop()
  
      var callback
      // if the stack is not empty yet, i.e., if this is not
      // the last route part, the callback standard callback is provided
      if (stack.length) {
        callback = done
      }
      // otherwise a slightly modified callback is provided
      else {
        callback = function() {
          done.end()
        }
        callback.redirect = done.redirect
        callback.render = function() {
          res.render.apply(res, [req.app._currentRoute].concat(Array.prototype.slice.call(arguments), finalize))
        }
      }
  
      // exectue the route part
      route.execute(req.app, req, res, callback)
    }