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