private void SaveDeletedCopies()
{
foreach (var itemCopy in _item.Copies.Values.ToList())
{
ItemCopyViewModel itemCopyViewModel;
if (!_itemCopiesViewModel.TryGetValue(itemCopy.CopyNo, out itemCopyViewModel)) // => Deleted Copy
{
_item.DeleteCopy(itemCopy.CopyNo);
}
}
}