Fatal error: Uncaught Error: Class "Drupal\FunctionalJavascriptTests\WebDriverTestBase" not found in /home/www/drupal8/test/core/tests/Drupal/FunctionalJavascriptTests/Ajax/MultiFormTest.php:17 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/tests/Drupal/FunctionalJavascriptTests/Ajax/MultiFormTest.php on line 17