def test_bool(self):
        prio_set_list = event._PrioritizedSetList()

        assert bool(prio_set_list) is False

        prio_set_list.add(0, None)
        assert bool(prio_set_list) is True
def draw(self, context):
        layout = self.layout

        userpref = context.user_preferences

        layout.prop(userpref, "active_section", expand=True)