document its parameters
Signed-off-by: Kefu Chai <kchai@redhat.com>
*
* Returns updated pg_stat_t if stats have changed since
* pg_stats_publish adding in unstable_stats.
+ *
+ * @param pg_stats_publish the latest pg_stat possessed by caller
+ * @param unstable_stats additional stats which should be included in the
+ * returned stats
+ * @return the up to date stats if it is different from the specfied
+ * @c pg_stats_publish
*/
std::optional<pg_stat_t> prepare_stats_for_publish(
const std::optional<pg_stat_t> &pg_stats_publish,