Fatal error: Uncaught Error: Class "Drupal\Tests\token\Kernel\KernelTestBase" not found in /home/www/drupal8/test/modules/token/tests/src/Kernel/BookTest.php:13 Stack trace: #0 {main} thrown in /home/www/drupal8/test/modules/token/tests/src/Kernel/BookTest.php on line 13