JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://documentcloud.github.com/underscore/underscore.js"></script>
<script src="https://raw.github.com/documentcloud/backbone/master/backbone.js"></script>

JavaScript

var Inventory = Backbone.Model.extend({},
    //STATIC
    {
        count: 0,
        foo: function() {
            alert('bar ' + this.count++);
        }
    });

var i = new Inventory({});
i.constructor.foo(); //This works!

var ExtendedInventory = Inventory.extend({});

var ei = new ExtendedInventory({});
ei.constructor.foo(); //THIS DOES NOT WORK