def test_edges_and_edge_count(self) -> None:
g = Graph([(1, 2), (2, 1), (2, 3), (3, 4)])
assert set(g.edges()) == {
g.get_edge(1, 2),
g.get_edge(2, 3),
g.get_edge(3, 4),
}, "edges should be (1, 2), (2, 3), (3, 4)"
assert g.edge_count == 3, "graph should have 3 edges"
def test_deepcopy(self) -> None:
g = Graph([(1, 2, {"color": "blue"}), (3, 4)])
g.add_vertex(42)
g_copy = g.deepcopy()
assert set(g.vertices()) == set(
g_copy.vertices()), "graph copy should have same vertices"
assert (
g[1] is not g_copy[1]
), "graph copy vertex objects should be distinct from original graph"
assert set(g.edges()) == set(
g_copy.edges()), "graph copy should have same edges"
assert g.get_edge(1, 2) is not g_copy.get_edge(
1, 2
), "graph copy edge objects should be distinct from original graph"
assert (
g.get_edge(1, 2)._attr == g_copy.get_edge(1, 2)._attr
), "graph copy edge object `_attr` dictionary should contain logically equal contents"
assert (
g.get_edge(1, 2)._attr is not g_copy.get_edge(1, 2)._attr
), "graph copy edge object `_attr` dictionary should be distinct from original graph"
