Baucis + Node.js

Good day everyone! I have some problems with understanding baucis (https://github.com/wprl/baucis). In middleware section I found that request can have isAuthenticated() method, but I'm not found any information about it in documentation and I got mistakes when called it. I need to realize this method in my code by myself? My code:

var citySchema = new mongoose.Schema({
  name: String
});

mongoose.model('City', citySchema);

var citiesController = baucis.rest('City');

citiesController.request(function (req, res, next) {
  if (req.isAuthenticated()) return next();
  return res.send(401);
});