Dúvidas com o Node.js

cars.js

module.exports = function(sequelize, Sequelize){

	var cars = sequelize.define('cars', {
		brand: Sequelize.STRING,
		model: Sequelize.STRING,
		price: Sequelize.STRING,
	});

	return cars;
};

resultado.json

{
  "id":1,
  "brand":"Peugeot",
  "model":"206 Sw Presence 1.4/ 1.4 Flex 8v 5p",
  "price":17500,
  "createdAt":"2014-05-16T21:57:18.000Z",
  "updatedAt":"2016-08-31T03:15:20.000Z",
  "userId":491
}

users.js

module.exports = function(sequelize, Sequelize){

	var users = sequelize.define('users', {
		name: Sequelize.STRING
	},{
		classMethods: {
			associate: function(models){
				users.hasMany(models.cars);
			}
		}
	});

	return users;
};