Fatal error: Uncaught Error: Interface "Drupal\Component\FileCache\FileCacheBackendInterface" not found in /home/www/drupal8/test/core/tests/Drupal/Tests/Component/FileCache/StaticFileCacheBackend.php:10 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/tests/Drupal/Tests/Component/FileCache/StaticFileCacheBackend.php on line 10