def __repr__(self):
        return "<NamedRequirements({}{})>".format(
            self.name,
            ", filename='{}'".format(self.filename.name) if self.filename
            else "")
def __init__(self, name: str, get_converter: t.Optional[t.Callable] = None) -> None:
        self.__name__ = name
        self.get_converter = get_converter