title: Symfony2 - Get an entity instead of PersistentCollection in twig
body: <p>I'm using symfony2, and I can't manage to get my related entity in twig.</p>
  
  <p>So I have my main entity, let's call it Post, which has a OneToMany relation : </p>
  
  <pre><code>/**
   * @ORM\OneToMany(targetEntity="Comment", mappedBy="Post", cascade={"persist", "remove"})
   */
  private $comments;
  </code></pre>
  
  <p>And I'm passing it to twig with my controller, I can access every property, but when I try to access a property with relations like "Comment", i'm getting a  <em>"Doctrine\ORM\PersistentCollection)"</em>  which has a lot of private property, and I can't manage to get the properties of this related entity...</p>
  
  <p>I'm a little confused, and I don't know what I'm doing wrong...</p>