@classmethod
def load(cls, filename: str, *, bind, _groupby_section=_tools.groupby_itemgetter(0)):
    select_values = sa.select(Config.section, Config.option, Config.value).filter_by(filename=filename).order_by('section', 'option')
    result = _backend.iterrows(select_values, bind=bind)
    return {section: {option: value for (_, option, value) in grp} for (section, grp) in _groupby_section(result)}
@classmethod
def load(cls, filename: str, *, bind, _groupby_section=_tools.groupby_itemgetter(0)):
    select_values = sa.select(Config.section, Config.option, Config.value).filter_by(filename=filename).order_by('section', 'option')
    result = _backend.iterrows(select_values, bind=bind)
    return {section: {option: value for (_, option, value) in grp} for (section, grp) in _groupby_section(result)}