Fatal error: Uncaught Error: Class "Drupal\KernelTests\Core\File\FileTestBase" not found in /home/qcsvlel/www/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php:20 Stack trace: #0 {main} thrown in /home/qcsvlel/www/core/modules/migrate/tests/src/Kernel/process/DownloadTest.php on line 20