[AdminListBundle] fixes forgotten commit new feature changeablelimiti…

…nterface (#1967)

src/Kunstmaan/AdminListBundle/Twig/AdminListTwigExtension.php

@@ -27,6 +27,27 @@ public function getFunctions()
         ];
     }
 
+    /**
+     * {@inheritdoc}
+     */
+    public function getTests()
+    {
+        return [
+            new \Twig_SimpleTest('instanceof', [$this, 'isInstanceOf']),
+        ];
+    }
+
+    /**
+     * @param object $object
+     * @param string $class
+     *
+     * @return bool
+     */
+    public function isInstanceOf($object, $class)
+    {
+        return $object instanceof $class;
+    }
+
     /**
      * Renders the HTML for a given view
      *