title: Set controller property to first model
body: <p>I want to set a controller property to the first object of the models but can't get the syntax right.</p>
  
  <p>My application route...</p>
  
  <pre><code>model: function(){
      return this.store.find('group');
  }
  </code></pre>
  
  <p>And then in my application controller, I'm trying something like...</p>
  
  <pre><code>activeGroup: function(){
          return this.get('model.firstObject');
      },
  </code></pre>
  
  <p>I've got a function a little later to set activeGroup to whichever is chosen, but I want it to be set as the first (or any) class by default.</p>
  
  <p>Thanks!</p>