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_ellipses(figure, visualizer, clusters, covariances, means):
        ax = figure.get_axes()[0]