Fatal error: Uncaught Error: Class "Drupal\Tests\rest\Functional\FileUploadResourceTestBase" not found in /home/www/drupal8/test/core/modules/file/tests/src/Functional/FileUploadJsonCookieTest.php:11 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/file/tests/src/Functional/FileUploadJsonCookieTest.php on line 11