private void _save()
 {
     foreach (var aclRightViewmodel in Rights)
     {
         if (aclRightViewmodel.IsModified)
         {
             aclRightViewmodel.Save();
         }
     }
     foreach (var right in _originalRights)
     {
         if (Rights.All(r => r.Right != right))
         {
             _engine.DeleteRight(right);
         }
     }
 }