Fatal error: Uncaught Error: Class "Drupal\file_test\StreamWrapper\DummyRemoteStreamWrapper" not found in /home/www/drupal8/test/core/modules/file/tests/file_test/src/StreamWrapper/DummyRemoteReadOnlyStreamWrapper.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/file/tests/file_test/src/StreamWrapper/DummyRemoteReadOnlyStreamWrapper.php on line 10