Fatal error: Uncaught Error: Class "Drupal\Core\Field\FieldItemBase" not found in /home/qcsvlel/www/core/tests/Drupal/Tests/Core/Entity/StubFieldItemBase.php:13 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/tests/Drupal/Tests/Core/Entity/StubFieldItemBase.php on line 13