def test_lookup(self):
        assert event.Priority.lookup(event.Priority.CORE) is event.Priority.CORE
        assert event.Priority.lookup(event.Priority.CORE.value) is event.Priority.CORE
        assert event.Priority.lookup(-12312412) == -12312412
def get_evolution_covariances(self):
        """!
        @return (list) Covariance matrix (or variance in case of one-dimensional data) of each cluster on each step of clustering.