Fatal error: Uncaught Error: Class "Drupal\Tests\rest\Functional\EntityResource\EntityResourceTestBase" not found in /home/www/drupal8/test/core/modules/aggregator/tests/src/Functional/Rest/FeedResourceTestBase.php:9 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/aggregator/tests/src/Functional/Rest/FeedResourceTestBase.php on line 9