Issue #2913459 by Eric_A: drupal/core-class-finder missing in ComposerIntegrationTest

core/tests/Drupal/Tests/ComposerIntegrationTest.php

@@ -47,6 +47,7 @@ protected function getPaths() {
       $this->root . '/core/lib/Drupal/Component/Annotation',
       $this->root . '/core/lib/Drupal/Component/Assertion',
       $this->root . '/core/lib/Drupal/Component/Bridge',
+      $this->root . '/core/lib/Drupal/Component/ClassFinder',
       $this->root . '/core/lib/Drupal/Component/Datetime',
       $this->root . '/core/lib/Drupal/Component/DependencyInjection',
       $this->root . '/core/lib/Drupal/Component/Diff',