Fatal error: Uncaught Error: Class 'Sabre\DAV\Collection' not found in /home/malert/WebDAV/vendor/sabre/dav/tests/Sabre/DAV/Mock/Collection.php:22 Stack trace: #0 {main} thrown in /home/malert/WebDAV/vendor/sabre/dav/tests/Sabre/DAV/Mock/Collection.php on line 22