def METHOD_NAME(tmpdir):
    with make_includes(str(tmpdir)) as includes:
        _yaml.roundtrip_dump(
            {"(@)": ["a.yml", "b.yml"], "test": {"(=)": ["Overwritten"]}}, str(tmpdir.join("main.yml"))
        )
        main = _yaml.load(str(tmpdir.join("main.yml")), shortname=None)
        # a.yml
        _yaml.roundtrip_dump(
            {"test": ["some useless", "list", "to be overwritten"], "foo": "should not be present"},
            str(tmpdir.join("a.yml")),
        )
        # b.yaml isn't going to have a 'test' node to overwrite
        _yaml.roundtrip_dump({"foo": "should be present"}, str(tmpdir.join("b.yml")))
        includes.process(main)
        assert main.get_str_list("test") == ["Overwritten"]
        assert main.get_str("foo") == "should be present"