reverted:
--- b/core/modules/language/tests/src/Functional/LanguageTourTest.php
+++ a/core/modules/language/src/Tests/LanguageTourTest.php
@@ -1,6 +1,6 @@
 <?php
 
+namespace Drupal\language\Tests;
-namespace Drupal\Tests\language\Functional;
 
 use Drupal\tour\Tests\TourTestBase;