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