virtual void SetPrivateData(JSContext* cx) {
          ENSURE(m_JSObject.initialized());
          JS::RootedObject ptrObj(cx, JS_NewObject(cx, &IGUIObject::store_class));
          JS_SetPrivate(ptrObj, (void*) this);
          JS::RootedValue ptrVal(cx);
          ptrVal.setObject(*ptrObj);
          /** I'm not entirely sure this static cast is needed but it seems conceptually correct, and safer */
          js::SetProxyReservedSlot(m_JSObject.get(), 0, ptrVal);
      };