Fatal error: Uncaught Error: Class 'Drupal\Tests\flag\Functional\FlagTestBase' not found in /var/www/html/tmp/contrib/flag/tests/src/Functional/UserFlagTypeTest.php:10 Stack trace: #0 {main} thrown in /var/www/html/tmp/contrib/flag/tests/src/Functional/UserFlagTypeTest.php on line 10