def METHOD_NAME(instance):
    """Returns a sortable title as a mxin of sortkey + lowercase sortable_title
    """
    title = sortable_title(instance)
    if safe_callable(title):
        title = title()
    sort_key = instance.getSortKey()
    if sort_key is None:
        sort_key = 999999
    return "{:010.3f}{}".format(sort_key, title)