def groups_option(f):
    new_func = click.option("-g", "--groups",
                            help="Comma-separated list of requirement groups "
                            "to include.")(f)
    return update_wrapper(new_func, f)
def serialize(self):
        s = []
        for v in self:
            if isinstance(v, BaseConfig):
                v = v.serialize()
            s.append(v)
        return s