def test_remove(self):
        prio_set_list = event._PrioritizedSetList()
        obj = (1,)

        prio_set_list.add(1, obj)
        assert prio_set_list
        prio_set_list.remove(obj)
        assert not prio_set_list

        with pytest.raises(ValueError) as excinfo:
            prio_set_list.remove(obj)
        excinfo.match(r"can not be found")
def _setup_drag(self, item):
    self._drag_and_drop_context.setup_drag(
      item.item_widget,
      self._get_drag_data,
      self._on_drag_data_received,
      [item],
      [item],
      self)