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