="#C2_L17" id=C2_L17></a></span></code></pre>
<p>The <code>completed</code> and <code>clearCompleted</code> methods both invoke the <code>filterBy</code> method, which is part of the <a href="https://api.emberjs.com/classes/Ember.ArrayController.html#method_filterProperty">ArrayController</a> API and returns an instance of <a href="https://api.emberjs.com/classes/Ember.Array.html">EmberArray</a> which contains only the items for which the callback returns true.  The <code>clearCompleted</code> method also i