public void UpdateSelectedContainer(ToggleButton checkBox, MultiSelectComboBoxItem container, bool select)
{
foreach (var si in SelectedItems)
{
var x = ContainerFromItem(si);
Debug.WriteLine(x);
}
var obj = ItemFromContainer(checkBox.GetVisualParent <MultiSelectComboBoxItem>());
if (obj != null)
{
checkBox.IsChecked = SelectedItems.Any(si => si == obj);
}
}
