def test_sorting():
    g = new_graph()

    key = lambda name: g.key("node", name)
    add = lambda name: g.add_node(key(name))
    node = lambda name: g.node(key(name))

    add("c")
    add("b")
    add("a")

    g.finalize()

    nodes = [node("b"), node("a"), node("c")]

    assert.eq(g.sorted_nodes(nodes, order_by = "key"), [
        node("a"),
        node("b"),
        node("c"),
    ])

    assert.eq(g.sorted_nodes(nodes, order_by = "def"), [
        node("c"),
        node("b"),
        node("a"),
    ])

test_sorting()