Fatal error: Uncaught Error: Class "Drupal\Tests\node\Kernel\Migrate\d6\MigrateNodeTestBase" not found in /home/www/drupal8/test/core/modules/migrate_drupal/tests/src/Kernel/d6/FollowUpMigrationsTest.php:13 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/modules/migrate_drupal/tests/src/Kernel/d6/FollowUpMigrationsTest.php on line 13