How to add annotations to stacked columns?

Hello,

I am using StackedColumnRenderableSeries and I need annotations like in Histogram example:

    private void Window_Loaded(object sender, RoutedEventArgs e)
    {
        var brushes = new Brush[] { Brushes.Red, Brushes.Green, Brushes.Blue, Brushes.Cyan, Brushes.Gray };
        var groups = new string[] { "Group 1", "Group 2", "Group 3" };
        var datas = new Dictionary<int, double[]>()
        {
            {1, new double[]{5.0, 4.0, 3.0, 2.0, 1.0}},
            {2, new double[]{1.0, 2.0, 3.0, 2.0, 1.0}},
            {3, new double[]{1.0, 2.0, 3.0, 4.0, 5.0}}
        };
        var data = new XyDataSeries<int, double>[brushes.Length];
        for (int i = 0; i < brushes.Length; i++)
        {
            data[i] = new XyDataSeries<int, double>();
        }
        foreach (var pair in datas)
        {
            for (int i = 0; i < pair.Value.Length; i++)
            {
                data[i].Append(pair.Key, pair.Value[i]);
            }
        }

        for (int i = 0; i < brushes.Length; i++)
        {
            var renderableSeries = new StackedColumnRenderableSeries()
            {
                Fill = brushes[i],
                DataSeries = data[i],
                StackedGroupId = brushes[i].ToString(),
            };
            sciChart.RenderableSeries.Add(renderableSeries);
        }
    }

How I can add annotation for each stacked grouped column? I attached the example with my Side-By-Side chart.

Ideally, I expected the annotations to be like in attached image.