public void PurgeFolders(UUID userId, IEnumerable <UUID> folderIds)
        {
            //this is a very uncommon operation, and normamly will only be executed
            //when a user selects individual items from their trash to purge
            //therefore, we will grab each folder individually
            List <InventoryFolderBase> folders = new List <InventoryFolderBase>();

            foreach (UUID id in folderIds)
            {
                InventoryFolderBase folder = _storage.GetFolderAttributes(id);

                if (folder != null)
                {
                    if (folder.Owner != userId)
                    {
                        throw new InventorySecurityException(String.Format("Not purging folder {0} for user {1}. User does not own the folder", folder.ID, userId));
                    }

                    folders.Add(folder);
                }
            }

            _storage.PurgeFolders(folders);
        }