Fatal error: Uncaught Error: Class "Drupal\Tests\system\FunctionalJavascript\OffCanvasTestBase" not found in /home/www/drupal8/test/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php:12 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/settings_tray/tests/src/FunctionalJavascript/SettingsTrayTestBase.php on line 12