title: Get collection length
body: <p>Using backbone.js and trying to get data from <code>postsList</code> array I got this in chrome console.log</p>
  
  <pre><code>d {length: 0, models: Array[0], _byId: Object, _byCid: Object, constructor: function…}
    _byCid: Object
    _byId: Object
    length: 9
    models: Array[9]
    __proto__: f
  </code></pre>
  
  <p>When I'm trying to use <code>console.log(postsList.length)</code> I get 0, but there are 9 models inside. I don't know how to get number of them. </p>