private static BitmapSource CreateDiagramImage(RadDiagram diagram, Rect enclosingBounds, Size returnImageSize, Brush backgroundBrush, Thickness margin, double dpi)
{
var virtualizationService = diagram.ServiceLocator.GetService <IVirtualizationService>() as VirtualizationService;
virtualizationService.ForceRealization();
diagram.UpdateLayout();
var itemsHost = diagram.FindChildByType <DiagramSurface>();
BitmapSource image = CreateWriteableBitmap(itemsHost, enclosingBounds, returnImageSize, backgroundBrush, margin, dpi);
virtualizationService.Virtualize();
diagram.UpdateLayout();
return(image);
}