Fatal error: Uncaught Error: Class "Behat\Mink\Selector\PartialNamedSelector" not found in /home/www/drupal8/test/core/tests/Drupal/Tests/HiddenFieldSelector.php:12 Stack trace: #0 {main} thrown in /home/www/drupal8/test/core/tests/Drupal/Tests/HiddenFieldSelector.php on line 12