Fatal error: Uncaught Error: Class "Drupal\Tests\Core\Render\RendererTestBase" not found in /home/www/drupal8/test/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php:9
Stack trace:
#0 {main}
thrown in /home/www/drupal8/test/core/tests/Drupal/Tests/Core/Render/RendererRecursionTest.php on line 9