Fatal error: Uncaught Error: Class "Drupal\Tests\media\Functional\MediaFunctionalTestBase" not found in /home/www/drupal8/test/core/modules/media/tests/src/Functional/MediaOverviewPageTest.php:14 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/media/tests/src/Functional/MediaOverviewPageTest.php on line 14