def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def get_dpo_proto(addr):
    if ip_address(addr).version == 6:
        return DpoProto.DPO_PROTO_IP6
    else:
        return DpoProto.DPO_PROTO_IP4