code: def to_jsondict(self):
          
          body = {"oxm_fields": [ofproto.oxm_to_jsondict(k, uv) for k, uv
                                 in self._fields2],
                  "length": self.length,
                  "type": self.type}
          return {self.__class__.__name__: body}
docs: Returns a dict expressing the flow match.