private void ListView_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            IList<object> removedList = (IList<object>)e.RemovedItems;
            foreach (object item in removedList)
            {
                selectedItems.Remove((NetworkLocation)item);
            }
            IList<object> addedList = (IList<object>)e.AddedItems;
            foreach (object item in addedList)
            {
                selectedItems.Add((NetworkLocation)item);
            }

            if (listView.SelectedItem != null)
            {
                NetworkLocation location = (NetworkLocation)listView.SelectedItem;
                editorGrid.DataContext = location.Clone();
            }
        }