+ /**
+ * Convert $timestamp to TS_MW or return null if the page was visited since then by $user
+ *
+ * Use this only on single-user methods (having higher read-after-write expectations)
+ * and not in places involving arbitrary batches of different users
+ *
+ * Usage of this method should be limited to WatchedItem* classes
+ *
+ * @param string|null $timestamp Value of wl_notificationtimestamp from the DB
+ * @param User $user
+ * @param LinkTarget $target
+ * @return string TS_MW timestamp or null
+ */
+ public function getLatestNotificationTimestamp( $timestamp, User $user, LinkTarget $target );