def METHOD_NAME():
    g = Graph()
    n1 = SomeTestResource(id="foo", tags={})
    n2 = SomeTestResource(id="bar", tags={})
    g.add_node(n1)
    g.add_node(n2)
    g.add_edge(n1, n2)
    assert g.is_acyclic_per_edge_type() is True
    g.add_edge(n2, n1)
    assert g.is_acyclic_per_edge_type() is False
    cycle = g.find_cycle()
    assert cycle == [
        EdgeKey(edge_type=EdgeType.default, src=n1, dst=n2),
        EdgeKey(edge_type=EdgeType.default, src=n2, dst=n1),
    ]