I have a little problem. I'm using backbone.js. I wrote this code like in example:

<script>

$(document).ready(function () {

    window.App = {

        Views: {},

        Models: {},

        Collections: {}

    }



    App.Collections.Users = Backbone.Collection.extend({

         model: App.Models.User,

         url: 'service'

    });

    App.Models.User = Backbone.Model.extend({});



    App.Views.App = Backbone.View.extend({

         initialize: function() {

             console.log( this.collection.toJSON() );

         }

    });



});

</script>

Than I started server and in browser console type this:

var x =new App.Collections.Users();

x.fetch()

And this follows to error: Uncaught TypeError: Cannot read property 'prototype' of undefined. But data is present in response. Details in picture. How to fix this?
Thanks for you answers.