def METHOD_NAME(
        style_config: tp.Optional[StyleConfig],
        container: 'ContainerOperandSequence',
        ) -> tp.Optional[StyleConfig]:
    # let user set style_config to None to disable styling
    if style_config is STYLE_CONFIG_DEFAULT:
        # if given the base class, get the derived CSS class
        return StyleConfigCSS(container)
    if style_config is None:
        return None
    return style_config