def METHOD_NAME(key: Callable[[Progress], Any]) -> List[str]:
    pt = ProgressTree("test")
    pt.add_progress(ProgressDone("a", 10, 10))
    pt.add_progress(ProgressDone("b", 8, 10))
    pt.add_progress(ProgressDone("c", 3, 10))
    pt.add_progress(ProgressDone("d", 1, 10))
    js = pt.to_json(key=key)
    return [x["name"] for x in js["parts"]]