def test_invalid_scalar_index(adata, index):
    # https://github.com/theislab/anndata/issues/619
    with pytest.raises(IndexError, match=r".*index.* out of range\."):
        _ = adata[index]
def __get_stop_condition(self):
        for covariance in self.__variances:
            if numpy.linalg.norm(covariance) == 0.0:
                return True