diff -r 907a52ed10e3 -r 8ceee38f5840 vm/src/test/java/org/apidesign/vm4brwsr/Instance.java
--- a/vm/src/test/java/org/apidesign/vm4brwsr/Instance.java	Sat Dec 01 10:35:24 2012 +0100
+++ b/vm/src/test/java/org/apidesign/vm4brwsr/Instance.java	Sun Dec 02 21:00:12 2012 +0100
@@ -117,4 +117,12 @@
         
         return constructor(x) == constructor(y);
     }
+    @JavaScriptBody(args = {}, body = "return {};")
+    private static Object jsObj() {
+        return null;
+    }
+    
+    public static boolean iofObject() {
+        return jsObj() instanceof Object;
+    }
 }