void ofputil_append_port_stat(struct list *replies,
const struct ofputil_port_stats *ops);
size_t ofputil_count_port_stats(const struct ofp_header *);
void ofputil_append_port_stat(struct list *replies,
const struct ofputil_port_stats *ops);
size_t ofputil_count_port_stats(const struct ofp_header *);