void OnEnable()
        {
            if (instance != null && instance != this)
            {
                Destroy(this);
            }

            instance = this;
        }
        void OnEnable()
        {
            if (instance != null && instance != this)
            {
                Destroy(this);
            }

            instance = this;

            if (!XmlLayoutUtilities.XmlLayoutConfiguration.UseXmlLayoutSelectableNavigation)
            {
                this.enabled = false;
            }
        }