Fatal error: Uncaught Error: Class "Drupal\Tests\migrate\Kernel\MigrateSqlSourceTestBase" not found in /home/qcsvlel/www/core/modules/search/tests/src/Kernel/Migrate/d6/SearchPageTest.php:15 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/search/tests/src/Kernel/Migrate/d6/SearchPageTest.php on line 15