Fatal error: Uncaught Error: Class "Drupal\Tests\rest\Functional\EntityResource\EntityResourceTestBase" not found in /home/www/drupal8/test/core/modules/system/tests/src/Functional/Rest/MenuResourceTestBase.php:8 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/system/tests/src/Functional/Rest/MenuResourceTestBase.php on line 8