public class SingleSelection : Object, ListModel, SelectionModel
GtkSingleSelection is an implementation of the SelectionModel interface that allows selecting a single element.
It is the default selection method used by list widgets in GTK.
Note that the selection is *persistent* -- if the selected item is removed and re-added in the same items_changed emission, it stays selected. In particular, this means that changing the sort order of an underlying sort model will preserve the selection.