How to use the bookshelf.mysqlAuth function in bookshelf

express = require('express'),
    bodyParser = require('body-parser'),
    cookieParser = require('cookie-parser'),
    cookieSession = require('cookie-session'),
    serveStatic = require('serve-static'),
    expressValidator = require('express-validator'),
    flash = require('connect-flash'),
    swig = require('swig'),
    passport = require('passport'),
    crypto = require('crypto'),
    Bookshelf = require('bookshelf'),
    messages = require('./util/messages');

var app = express();

Bookshelf.mysqlAuth = Bookshelf(knex);

app.use(cookieParser('halsisiHHh445JjO0'));
app.use(cookieSession({
    keys: ['key1', 'key2']
}));

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

app.use(expressValidator());
app.use(passport.initialize());
app.use(passport.session());
app.use(flash());
app.use(serveStatic('./public'));
//app.use(express.favicon(__dirname + '/public/images/shortcut-icon.png'));
app.use(messages());