Fatal error: Uncaught Error: Class "Drupal\KernelTests\Core\Database\DatabaseTestBase" not found in /home/www/drupal8/test/core/tests/Drupal/KernelTests/Core/Database/QueryTest.php:10
Stack trace:
#0 {main}
thrown in /home/www/drupal8/test/core/tests/Drupal/KernelTests/Core/Database/QueryTest.php on line 10