Fatal error: Uncaught Error: Class "Sabre\DAV\SimpleCollection" not found in /var/www/illumine/vendor/sabre/dav/tests/Sabre/DAV/Sync/MockSyncCollection.php:17 Stack trace: #0 {main} thrown in /var/www/illumine/vendor/sabre/dav/tests/Sabre/DAV/Sync/MockSyncCollection.php on line 17