Fatal error: Uncaught Error: Class "Drupal\Tests\media\Kernel\MediaKernelTestBase" not found in /home/www/drupal8/test/core/modules/media/tests/src/Kernel/OEmbedIframeControllerTest.php:12
Stack trace:
#0 {main}
thrown in /home/www/drupal8/test/core/modules/media/tests/src/Kernel/OEmbedIframeControllerTest.php on line 12