* @return string fetched message URL
* @throws \Friendica\Network\HTTPException\InternalServerErrorException
*/
- public static function fetchMissingActivity($url, $child = [])
+ public static function fetchMissingActivity(string $url, array $child = [])
{
if (!empty($child['receiver'])) {
$uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);