def METHOD_NAME(settings: "AppSettings", data: CFG = None) -> None:
    data = data or cfg
    logger.debug("storing\n(\n%s\n)", data)
    assert isinstance(data, CFG)
    for field in DC.fields(data):
        data_class = getattr(data, field.name)
        assert DC.is_dataclass(data_class)
        settings.store_dataclass(field.name.upper(), data_class)