Yes but the G_.selected is not what should be exposed to the user. I would further disagree about throwing an error when nothing is selected. This happens regularly when switching the content of a TreeView. It would be ok if one would throw a dedicated `NoSelectionException`that can be catched outside. But in this case this doesn't feel right.

The thing I am unsure is whether the return value of `gtk_tree_selection_get_selected` should be returned. Alternatively one can check for the iter if it is valid. But I decided against this because checking an iter requires the model this would be more inconvenient on the calling side.