Issue #3268612: StageValidationException does not provide a message based on validation results

package_manager/tests/modules/package_manager_test_validation/src/EventSubscriber/TestSubscriber.php

@@ -103,6 +103,15 @@ class TestSubscriber implements EventSubscriberInterface {
     }
   }
 
+  /**
+   * Computes the state key to use for a given event class.
+   *
+   * @param string $event
+   *   The event class.
+   *
+   * @return string
+   *   The state key under which to store the results for the given event.
+   */
   protected static function getStateKey(string $event) {
     $parts = explode('\\', $event);
     return static::STATE_KEY . array_pop($parts);