How to use the loopback.urlNotFound function in loopback

// Let express routes handle requests that were not handled
// by any of the middleware registered above.
// This way LoopBack REST and API Explorer take precedence over
// express routes.
app.use(app.router);

// The static file server should come after all other routes
// Every request that goes through the static middleware hits
// the file system to check if a file exists.
app.use(loopback.static(path.join(__dirname, 'public')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

/*
 * 4. Setup error handling strategy
 */

/*
 * EXTENSION POINT
 * Add your custom error reporting middleware here
 * Example:
 *   app.use(function(err, req, resp, next) {
 *     console.log(req.url, ' failed: ', err.stack);
 *     next(err);
 *   });
 */

// The ultimate error handler.

//custom auth middleware
//app.middleware('auth:before', ['/protected', '/api', '/me', '/_internal'], middleware.auth.authenticate);
var auth = oauth2.authenticate({session: false, scope: ['web', 'demo']});
app.middleware('auth:before', ['/protected', '/api', '/me', '/_internal'],
  auth);


//setting up proxy middleware
var proxy = require('./middleware/proxy');
var proxyOptions = require('./middleware/proxy/config.json');
app.middleware('routes:after', proxy(proxyOptions));


// that will be handled later down the chain.
app.middleware('final', loopback.urlNotFound());

// The ultimate error handler.
app.middleware('final', loopback.errorHandler());


app.start = function() {
  // start the web server
  return app.listen(function() {
    app.emit('started');
    console.log('Web server listening at: %s', app.get('url'));
  });
};

port: livereload
  }));
}

// boot scripts mount components like REST API
boot(app, __dirname);

// Mount static files like ngapp
// All static middleware should be registered at the end, as all requests
// passing the static middleware are hitting the file system
app.use(loopback.static(path.dirname(app.get('indexFile'))));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

// The ultimate error handler.
app.use(loopback.errorHandler());

// optionally start the app
app.start = function() {
  // start the web server
  return app.listen(function() {
    app.emit('started');
    console.log('Web server listening at: %s', app.get('url'));
  });
};

if (require.main === module) {
  app.start();
}

req.logout();
  res.redirect('/');
  console.log('Logged out', req.user)
});

// -- Mount static files here--
// All static middleware should be registered at the end, as all requests
// passing the static middleware are hitting the file system
// Example:
var path = require('path');
app.use(loopback.static(path.resolve(__dirname, '../client/www')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

// The ultimate error handler.
app.use(loopback.errorHandler());

app.start = function() {
  // start the web server
  return app.listen(function() {
    app.emit('started');
    console.log('Web server listening at: %s', app.get('url'));

    app.models.user.create({
      email: 'foo@bar.com',
      password: '123456',
      name: {givenName: 'Joseph', familyName: 'Toblerone'}
    });

app.get('/auth/account', function (req, res, next) {
  // redirect
  res.redirect(req.query.returnUrl);
});

// -- Mount static files here--
// All static middleware should be registered at the end, as all requests
// passing the static middleware are hitting the file system
// Example:
var path = require('path');
app.use(loopback.static(path.resolve(__dirname, '../client')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

// The ultimate error handler.
app.use(loopback.errorHandler());

app.start = function() {
  // start the web server
  return app.listen(function() {
    app.emit('started');
    console.log('Web server listening at: %s', app.get('url'));
  });
};

// start the server if `$ node server.js`
if (require.main === module) {
  app.start();
}

*       // send status response
 *     } else {
 *       next();
 *     }
 *   });
 */

// The static file server should come after all other routes
// Every request that goes through the static middleware hits
// the file system to check if a file exists.
app.use(loopback.static(path.join(__dirname, 'public')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

/*
 * 4. Setup error handling strategy
 */

/*
 * EXTENSION POINT
 * Add your custom error reporting middleware here
 * Example:
 *   app.use(function(err, req, resp, next) {
 *     console.log(req.url, ' failed: ', err.stack);
 *     next(err);
 *   });
 */

// The ultimate error handler.

*       // send status response
 *     } else {
 *       next();
 *     }
 *   });
 */

// The static file server should come after all other routes
// Every request that goes through the static middleware hits
// the file system to check if a file exists.
app.use(loopback.static(path.join(__dirname, 'public')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

/*
 * 4. Setup error handling strategy
 */

/*
 * EXTENSION POINT
 * Add your custom error reporting middleware here
 * Example:
 *   app.use(function(err, req, resp, next) {
 *     console.log(req.url, ' failed: ', err.stack);
 *     next(err);
 *   });
 */

// The ultimate error handler.

// Let express routes handle requests that were not handled
// by any of the middleware registered above.
// This way LoopBack REST and API Explorer take precedence over
// express routes.
app.use(app.router);

// The static file server should come after all other routes
// Every request that goes through the static middleware hits
// the file system to check if a file exists.
app.use(loopback.static(path.join(__dirname, 'public')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

/*
 * 4. Setup error handling strategy
 */

/*
 * EXTENSION POINT
 * Add your custom error reporting middleware here
 * Example:
 *   app.use(function(err, req, resp, next) {
 *     console.log(req.url, ' failed: ', err.stack);
 *     next(err);
 *   });
 */

// The ultimate error handler.

// LoopBack REST interface
  app.use(app.get('restApiRoot'), loopback.rest());
// API explorer (if present)
  try {
    var explorer = require('loopback-explorer')(app);
    app.use('/explorer', explorer);
    app.once('started', function (baseUrl) {
      console.log('Browse your REST API at %s%s', baseUrl, explorer.route);
    });
  } catch (e) {
    console.log(
      'Run `npm install loopback-explorer` to enable the LoopBack explorer'
    );
  }

  app.use(loopback.urlNotFound());
  app.use(loopback.errorHandler());

  if (require.main === module) {
    app.start();
  }

});

// Let express routes handle requests that were not handled
// by any of the middleware registered above.
// This way LoopBack REST and API Explorer take precedence over
// express routes.
app.use(app.router);

// The static file server should come after all other routes
// Every request that goes through the static middleware hits
// the file system to check if a file exists.
app.use(loopback.static(path.join(__dirname, 'public')));

// Requests that get this far won't be handled
// by any middleware. Convert them into a 404 error
// that will be handled later down the chain.
app.use(loopback.urlNotFound());

/*
 * 4. Setup error handling strategy
 */

/*
 * EXTENSION POINT
 * Add your custom error reporting middleware here
 * Example:
 *   app.use(function(err, req, resp, next) {
 *     console.log(req.url, ' failed: ', err.stack);
 *     next(err);
 *   });
 */

// The ultimate error handler.