def test_order(self):
        assert (event.Priority.PRE_CORE
                > event.Priority.CORE
                > event.Priority.POST_CORE
                > event.Priority.PRE_DEFAULT
                > event.Priority.DEFAULT
                > event.Priority.POST_DEFAULT)
def __notify(self):
        if self.__observer is not None:
            self.__observer.notify(self.__means, self.__variances, self.__clusters)