JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://underscorejs.org/underscore-min.js"></script>
<script src="http://documentcloud.github.com/backbone/backbone-min.js"></script>

JavaScript

var Module = Backbone.Model.extend();

var ModuleCollection = Backbone.Collection.extend({
    model: Module
});

var modules = new ModuleCollection;

modules.add({foo: 'foo'},{foo: 'bar'});

console.log(modules instanceof Backbone.Collection);

var filtered = modules.filter(function(module) {
    return module.get('foo') == 'bar';
});

console.log(filtered instanceof Backbone.Collection);