title: where the createFormBuilder()?
body: <p>I am using symfony2 and FOSUserBundle</p>
  
  <p>I want to use 'createFormBuilder' in ProfileController</p>
  
  <pre><code>use Symfony\Bundle\FrameworkBundle\Controller\Controller;
  
  use Symfony\Component\HttpFoundation\Response;
  use Acme\UserBundle\Entity\AttrMutor;
  
  
  class ProfileController extends ContainerAware
  {
        $attrMutor = new AttrMutor();
        $form = $this-&gt;createFormBuilder($attrMutor);    
  </code></pre>
  
  <p>it shows such as </p>
  
  <pre><code>FatalErrorException: Error: Call to undefined method Acme\UserBundle\Controller\ProfileController::createFormBuilder() 
  </code></pre>
  
  <p>How can I solve this?</p>
  
  <p>I can use $this->createFormBuilder in other Controller such as </p>
  
  <pre><code>class DefaultController extends Controller
  {
        $attrMutor = new AttrMutor();
        $form = $this-&gt;createFormBuilder($attrMutor);   //OK
  </code></pre>
  
  <p>I think there is a hint in differences between extends ContainerAware and extends Controller</p>