def serialize_tail(self):
        flags = ((self.i_flag & 0x1) << 2) ^ \
                ((self.m_flag & 0x1) << 1) ^ \
                (self.ms_flag & 0x1)
        head = bytearray(struct.pack(self._PACK_STR, self.mtu,
                                     self.options, flags,
                                     self.sequence_number))
        try:
            return head + reduce(lambda a, b: a + b,
                                 (hdr.serialize() for hdr in self.lsa_headers))
        except __HOLE__:
            return head
dataset/ETHPy150Open osrg/ryu/ryu/lib/packet/ospf.py/OSPFDBDesc.serialize_tail