How to create a Nested Donut chart

The following example demonstrates how to create a Nested Donut chart.
To do this, it is necessary to assign the ChartControl.Diagram property to SimpleDiagram2D, and then add two NestedDonutSeries2D objects with points to the diagram's Diagram.Series collection.
Also, this example shows how to change the color of each series point according to its values using the ChartControl.CustomDrawSeriesPoint event. As a result, segments of an outer donut representing kinds of products are colored with a specific Product group color (an inner donut).