def test_pg_has_no_property_by_default(): pg = PropertyGraph() assert len(tuple(pg.vertex_property_names())) == 0 assert len(tuple(pg.edge_property_names())) == 0 assert len(tuple(pg.graph_property_names())) == 0 assert len(tuple(pg.vertex_properties())) == 0 assert len(tuple(pg.edge_properties())) == 0 assert len(tuple(pg.graph_properties())) == 0