LUA waiting with await

LuaExample.xaml.cs

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            this.Loaded += MainWindow_Loaded;
        }

        private void MainWindow_Loaded(object sender, RoutedEventArgs e)
        {
            ScriptBox.Text =

            @"
            return function(j)
            for i=10,20 do 
            paint(i*2) 
            wait(j);
            coroutine.yield()
            end
            end";
                    }

        public async void Wait(int j)
        {
            await Task.Delay(500);
            coroutines[j].Coroutine.Resume();

        }

        double i = 0;
        int j = 0;
        Script script;
        List<DynValue> coroutines = new List<DynValue>();
        Random random = new Random(DateTime.Now.Millisecond);

        private void AddEllipse(double diameter)
        {
            MainCanvas.Dispatcher.Invoke(() =>
            {
                var offset = i;
                i += 0.1;
                
                var color = Color.FromArgb(0xFF, (byte)random.Next(0, 128), 
                (byte)random.Next(0, 128), (byte)random.Next(0, 128));

                var el = new Ellipse()
                {
                    Fill = new SolidColorBrush(color),
                    Width = diameter,
                    Height = diameter,
                    VerticalAlignment = VerticalAlignment.Top,
                    HorizontalAlignment = HorizontalAlignment.Left
                };

                Canvas.SetLeft(el, offset + diameter );
                Canvas.SetTop(el, diameter);

                MainCanvas.Children.Add(el);
            });


        }

        int k = 0;
        private async void RunScript_Click(object sender, RoutedEventArgs e)
        {
            k++;
            ScriptsBlock.Text = $"Scripts {k}";

           var scriptCode = ScriptBox.Text;
           script = new Script();

            try
            {
                script.Globals["paint"] = (Action<double>)(AddEllipse);
                script.Globals["wait"] = (Action<int>)(Wait);

                DynValue function = script.DoString(scriptCode);
                var coroutine = script.CreateCoroutine(function);
                coroutines.Add(coroutine);
                coroutine.Coroutine.Resume(j);
                j++;
            }
            catch (Exception ex)
            {
                
            }


        }
    }