title: Sonata User - Customize admin query with security
body: <p>I have extended SonataUserBundle and I'd like to customize the Admin query to restrict the list:</p>
  
  <pre class="lang-php prettyprint-override"><code>class UserAdmin extends BaseUserAdmin
  {
  // ...
      public function createQuery($context = 'list')
      {
          $query = parent::createQuery($context);
          $query-&gt;andWhere( 
              $query-&gt;expr()-&gt;eq($query-&gt;getRootAlias().'.company', ':comp')
          );
          $query-&gt;setParameter('comp', $securityContext-&gt;user-&gt;getCompany());
          return $query;
      }
  // ...
  }
  </code></pre>
  
  <p>Here, I'm trying to make the user only see users from his company.<br>
  But <code>$securityContext</code> is not set.</p>
  
  <p>Can someone tell how to inject the security context into my admin class ?</p>