Fatal error: Uncaught Error: Class "Drupal\Tests\rdf\Kernel\Field\FieldRdfaTestBase" not found in /home/www/drupal8/test/core/modules/rdf/tests/src/Kernel/Field/NumberFieldRdfaTest.php:12 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/rdf/tests/src/Kernel/Field/NumberFieldRdfaTest.php on line 12