title: How to retrieve full role hierarchy in Symfony
body: <p>I'm using symfony2 role hierarchy, it works well, but in order to perform some changes, i have to retrieve the <code>role_hierarchy</code> set up in my <code>security.yml</code>.</p>
  
  <pre><code>role_hierarchy:
  ROLE_USER: [ROLE_ACCESS_USER, ROLE_ACCESS_DATA, ROLE_ACCESS_PRODUCT]
  </code></pre>
  
  <p>Using <code>getRoles()</code> just return <code>ROLE_USER</code>, how can i know in my code that <code>ROLE_USER</code> is made with <code>ROLE_ACCESS_USER, ROLE_ACCESS_DATA, ROLE_ACCESS_PRODUCT</code>?</p>
  
  <p>thanks for helping.</p>