$create: Whether or not the restoration caused the page to be created (i.e. it
didn't exist before).
$comment: The comment associated with the undeletion.
-$oldPageId: ID of page previously deleted (from archive table)
+$oldPageId: ID of page previously deleted (from archive table). This ID will be used
+ for the restored page.
+$restoredPages: Set of page IDs that have revisions restored for this undelete,
+ with keys being page IDs and values are 'true'.
'ArticleUndeleteLogEntry': When a log entry is generated but not yet saved.
$pageArchive: the PageArchive object
$performer: User who performed the change, false if via autopromotion
$reason: The reason, if any, given by the user performing the change,
false if via autopromotion.
+$oldUGMs: An associative array (group name => UserGroupMembership object) of
+the user's group memberships before the change.
+$newUGMs: An associative array (group name => UserGroupMembership object) of
+the user's current group memberships.
'UserIsBlockedFrom': Check if a user is blocked from a specific page (for
specific block exemptions).