code: def pre_serialize(self, raw, pkt, i):
          '''
          Set length of the header based on
          '''
          self.length = len(raw) + OpenflowHeader._MINLEf pre_serialize(self, raw, pkt, i):
          '''
          Set length of the header based on
          '''
          self.length = len(raw) + OpenflowHeader._MINLEN
docs: Set length of the header based on