def __repr__(self):
        return "<NamedRequirements({}{})>".format(
            self.name,
            ", filename='{}'".format(self.filename.name) if self.filename
            else "")
def encode(self):
        if self.version == 6:
            return {'ip6': self.ip_addr}
        else:
            return {'ip4': self.ip_addr}