public function __construct(RoleHierarchyInterface $roleHierarchy, $prefix = 'ROLE_')
 {
     $this->roleHierarchy = $roleHierarchy;
     parent::__construct($prefix);
 }
 /**
  * @param RoleCollection $roleCollection
  * @param string         $prefix
  */
 public function __construct(RoleCollection $roleCollection, $prefix = 'ROLE_')
 {
     parent::__construct($prefix);
     $this->roleCollection = $roleCollection;
 }