/**
  * @see AuthorizationPolicy::effect()
  */
 function effect()
 {
     // Retrieve the user from the session.
     $request = $this->getRequest();
     $user = $request->getUser();
     if (!is_a($user, 'User')) {
         return AUTHORIZATION_DENY;
     }
     // Execute handler operation checks.
     return parent::effect();
 }