diff --git a/core/lib/Drupal/Core/Routing/NullGenerator.php b/core/lib/Drupal/Core/Routing/NullGenerator.php
index 9d6db83..a3b7416 100644
--- a/core/lib/Drupal/Core/Routing/NullGenerator.php
+++ b/core/lib/Drupal/Core/Routing/NullGenerator.php
@@ -27,8 +27,15 @@ public function __construct(RequestStack $request_stack) {
   /**
    * {@inheritdoc}
    *
-   * generate(), generateFromRoute(), and getPathFromRoute() all call this
+   * Functions generate(), generateFromRoute(), and getPathFromRoute() all call this
    * protected method.
+   *
+   * @param string $name
+   *   The special string that generates a routing path.
+   *   This defines the following special routes:
+   *   - <front>: The site's front page.
+   *   - <current>: The current page.
+   *   - <none>: The path that make links relative to the current URL.
    */
   protected function getRoute($name) {
     if ($name === '<front>') {