Sorting SelectedItems based on original collection

        private void CopyExecuted(object sender, ExecutedRoutedEventArgs e)
        {
            ListBox box = sender as ListBox;

            HashSet<object> allItems = new HashSet<object>(box.Items.OfType<object>());
            HashSet<object> selectedItems = new HashSet<object>(box.SelectedItems.OfType<object>());

            IEnumerable<object> sortedItems = allItems.Where(i => selectedItems.Contains(i));

            string log = string.Join("\r\n", sortedItems);
            Clipboard.SetText(log);
        }