def test_arbitrary_node(): # given g = UndirectedGraph() g.add_edge(1, 2) g.add_edge(2, 3) u = g.arbitrary_node() assert u in g.nodes
def test_arbitrary_node_raises_if_graph_empty(): # given g = UndirectedGraph() with pytest.raises(DoesNotExistError): u = g.arbitrary_node()