Fatal error: Uncaught Error: Class "Drupal\migrate_tools\Form\MigrationFormBase" not found in /home/www/drupal8/test/modules/migrate_tools/src/Form/MigrationEditForm.php:15 Stack trace: #0 {main} thrown in /home/www/drupal8/test/modules/migrate_tools/src/Form/MigrationEditForm.php on line 15