private void FilterBox_Loaded(object sender, RoutedEventArgs e)
        {
            ComboBox b = sender as ComboBox;

            b.IsTextSearchEnabled = false;
            b.ItemsSource         = GroupTypes.ToList();
        }
        private void GroupComboBoxLoaded(object sender, RoutedEventArgs e)
        {
            ComboBox box = sender as ComboBox;

            box.ItemsSource = GroupTypes.ToList();
        }