Issue #3458360: Do not use ControllerBase as parent class for RestExampleHelpController

modules/rest_example/src/Controller/RestExampleHelpController.php

@@ -2,7 +2,7 @@
 
 namespace Drupal\rest_example\Controller;
 
-use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\examples\Utility\DescriptionTemplateTrait;
 
 /**
@@ -10,10 +10,17 @@
  *
  * @ingroup rest_example
  */
-class RestExampleHelpController extends ControllerBase {
+class RestExampleHelpController implements ContainerInjectionInterface {
 
   use DescriptionTemplateTrait;
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static();
+  }
+
   /**
    * {@inheritdoc}
    */