'Tests that using a MultiGraph creates multiple edges.'

def test_create_multigraph(self):

    G = nx.path_graph(3, create_using=nx.MultiGraph())
    actual = nx.contracted_nodes(G, 0, 2)
    expected = nx.MultiDiGraph()
    expected.add_edge(0, 1)
    expected.add_edge(0, 1)
    assert_edges_equal(actual.edges, expected.edges)
