title: FOSUserBundle authenticate selected user
body: <p>I would authenticate a user in a very direct way (FOSUserBundle, Symfony2.2). I'am trying with a trivial example, but it doesn't work:</p>
  
  <pre><code>...
  use FOS\UserBundle\Controller\RegistrationController as RegController;
  ...
  class DefaultController extends Controller{
  ...
  public function indexAction(){
  $route = 'first_set_profile';
  $url = $this-&gt;container-&gt;get('router')-&gt;generate($route);
  $response = new RedirectResponse($url);
  $userManager = $this-&gt;get('fos_user.user_manager');
  $userToLogIn = $userManager-&gt;findUserByEmail('aa@bb.com');
  new RegController(authenticateUser($userToLogIn, $response));
  ...
  }
  </code></pre>
  
  <p>This script is running, but it is not authenticate the user with email aa@bb.com...</p>
  
  <p>Thanks</p>