Fatal error: Uncaught Error: Class "Drupal\Tests\language\Functional\Rest\ConfigurableLanguageResourceTestBase" not found in /home/www/drupal8/test/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageJsonBasicAuthTest.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/language/tests/src/Functional/Rest/ConfigurableLanguageJsonBasicAuthTest.php on line 10