async def METHOD_NAME(matcher: Matcher, state: T_State):
    if not platform_manager[state["platform"]].categories:
        matcher.set_arg("raw_cats", None)  # type: ignore
        state["cats"] = []
        return
    state["_prompt"] = "请输入要订阅的类别，以空格分隔，支持的类别有：{}".format(
        " ".join(list(platform_manager[state["platform"]].categories.values()))
    )