Multi-tenant app example with prefixed collections

multitenant_server_single_db.js

var express = require('express');
var mongoose = require('mongoose-multitenant')();

mongoose.connect('mongodb://localhost/multitenant', { server: { poolSize: 5 } });

var app = express();

app.use(express.bodyParser());

app.post('/posts', function (req, res) {
	Author(req.query.tenant).findOne().exec().then(function (author) {
		req.body.author = author.id;
		Post(req.query.tenant).create(req.body).then(function (post) {
	    res.json(post);
		}, function (err) {
			console.log('Post error');
			res.send(500, err);
		});
	});
});

app.get('/posts', function (req, res) {
  Post(req.query.tenant).count().exec().then(function (count) {
    res.send({ count: count });
  });
});

app.listen(3000);

console.log('Listening...');

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

mongoose.mtModel('Author', authorSchema);

Author = function (prefix) {
	return mongoose.mtModel(prefix + '.Author');
};

var postSchema = mongoose.Schema({
  name: String,
  date: { type: Date, default: Date.now },
  author: { type: mongoose.Schema.Types.ObjectId, ref: 'Author', $tenant: true },
});

mongoose.mtModel('Post', postSchema);

Post = function (prefix) {
  return mongoose.mtModel(prefix + '.Post');
};

// insert tenants
for (var i = 0; i < 40; i++) {
	Author('t' + i).create({ name: 'Author ' + i });
}

what version of mongoose did this run on? I get "Cannot read property 'connect' of undefined"