Issue #3194199: Drupal 9 compatibility

Closes #3194199

src/Entity/Decorators/ImageStyleDecoratorBase.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\entity_decorator\Entity\Decorators;
 
+use Drupal\Core\Config\Entity\ConfigEntityInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\entity_decorator\Traits\Core\Plugin\ObjectWithPluginCollectionTrait;
 use Drupal\entity_decorator\Traits\DecoratorTrait;
@@ -62,4 +63,11 @@ abstract class ImageStyleDecoratorBase implements ImageStyleInterface, EntityWit
     RootImageStyle::postLoad($storage, $entities);
   }
 
+  /**
+   * @inheritDoc
+   */
+  public static function sort(ConfigEntityInterface $a, ConfigEntityInterface $b) {
+    return RootImageStyle::sort($a, $b);
+  }
+
 }