bookshelf previous attrs

test.js

var assert = require('assert');
var knex = require('knex')({
    client: 'sqlite3',
    connection: {filename: ':memory:'}
});
var bookshelf = require('bookshelf')(knex);
var User = bookshelf.Model.extend({
    tableName: 'users',
    initialize: function () {
        this.on('updated', function (user) {
            console.log('prev attrs on updated', user.previousAttributes());
        });
    }
});

var Users = bookshelf.Collection.extend({
    model: User
});

return knex.schema.createTable('users', function (table) {
    table.increments();
    table.text('status').notNullable();
    table.text('name').notNullable();
}).then(function () {
    return knex('users').insert({status: 'active', name: 'ralf'});
}).then(function () {
    return new User({id: 1}).fetch();
}).then(function (user) {
    assert.strictEqual(user.get('status'), 'active');
    user.set('status', 'active');
    return user.save();
}).then(function () {
    console.log('all done model');

    return Users.forge({id: 1}).fetch();
}).then(function (users) {
    console.log('prev attrs on collection fetch', users.models[0].previousAttributes());
}).catch(function (err) {
    console.log(err);
    console.log(err.stack);
}).finally(function () {
    process.exit();
});