Fatal error: Uncaught Error: Class "Drupal\Tests\rest\Functional\ResourceTestBase" not found in /home/www/drupal8/test/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php:74 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/rest/tests/src/Functional/EntityResource/EntityResourceTestBase.php on line 74