System.Windows.UIElement.EnsureDesignMode C# (CSharp) Method

        static void EnsureDesignMode()
        {
            // NOTE:
            // If you ended up here from drt 539 you should know
            // it doesn't pass on Silverlight but MobileStubsTests
            // does so tread lightly

            if (//Int32.Parse (Deployment.Current.RuntimeVersion.Split('.')[0]) < 4 &&
                !DesignerProperties.GetIsInDesignMode (Application.Current.RootVisual))
                throw new NotImplementedException ();
        }