graph = <swh.graph.graph.Graph object at 0x7f8ecf5ada58> def test_visit_nodes(graph): actual = list( graph["swh:1:rel:0000000000000000000000000000000000000010"].visit_nodes( > edges="rel:rev,rev:rev" ) ) .tox/py3/lib/python3.7/site-packages/swh/graph/tests/test_graph.py:56: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ self = <swh:1:rel:0000000000000000000000000000000000000010> direction = 'forward', edges = 'rel:rev,rev:rev', max_edges = 0 def visit_nodes(self, direction="forward", edges="*", max_edges=0): for node in call_async_gen( > self.graph.backend.visit_nodes, direction, edges, self.id, max_edges ): E AttributeError: 'Backend' object has no attribute 'visit_nodes' .tox/py3/lib/python3.7/site-packages/swh/graph/graph.py:88: AttributeError