Adjust PHPDoc as suggested

lib/private/group.php

@@ -183,7 +183,7 @@ class OC_Group {
 	 *
 	 * This function fetches all groups a user belongs to. It does not check
 	 * if the user exists at all.
-	 * @deprecated Use \OC::$server->getGroupManager->getuserGroupIds($user)
+	 * @deprecated Use \OC::$server->getGroupManager->getUserGroupIds($user)
 	 */
 	public static function getUserGroups($uid) {
 		$user = self::getUserManager()->get($uid);

lib/private/group/manager.php

@@ -210,7 +210,7 @@ class Manager extends PublicEmitter implements IGroupManager {
 	}
 
 	/**
-	 * @param \OC\User\User $user
+	 * @param \OC\User\User|null $user
 	 * @return \OC\Group\Group[]
 	 */
 	public function getUserGroups($user) {

lib/public/igroupmanager.php

@@ -93,7 +93,7 @@ interface IGroupManager {
 	public function search($search, $limit = null, $offset = null);
 
 	/**
-	 * @param \OCP\IUser $user
+	 * @param \OCP\IUser|null $user
 	 * @return \OCP\IGroup[]
 	 * @since 8.0.0
 	 */