Fatal error: Uncaught Error: Class "Drupal\migrate_drupal\Plugin\migrate\source\DrupalSqlBase" not found in /home/www/drupal8/test/core/modules/field/src/Plugin/migrate/source/d7/Field.php:21
Stack trace:
#0 {main}
thrown in /home/www/drupal8/test/core/modules/field/src/Plugin/migrate/source/d7/Field.php on line 21