Node BoundaryCurve has no effect

I'm trying to define the size of a node explicitly. I've tried setting the label width/height as well as setting the node's boundarycurve. Both does to seem to make any effect of the node size.
Below is my sample code.
What am I missing?

        Microsoft.Msagl.Drawing.Graph graph = new Microsoft.Msagl.Drawing.Graph("");
        graph.AddEdge("A", "B");
        graph.AddEdge("B", "C");

        int nwidth = 100;
        int nheight = 100;

        var geometryGraph = graph.CreateGeometryGraph();
        var n = graph.FindNode("A");
        n.Label.GeometryLabel = new Microsoft.Msagl.Core.Layout.Label();
        n.Label.GeometryLabel.Width = nwidth;
        n.Label.GeometryLabel.Height = nwidth;
        n.Label.Width = nwidth;
        n.Label.Height = nheight;
        int r = n.Attr.LabelMargin;
        n.GeometryNode.BoundaryCurve = CurveFactory.CreateRectangleWithRoundedCorners(nwidth + r * 2, nheight + r * 2, r, r, new Point());

        graph.Attr.LayerDirection = LayerDirection.LR;
        geometryGraph.UpdateBoundingBox();

        Microsoft.Msagl.GraphViewerGdi.GraphRenderer renderer = new Microsoft.Msagl.GraphViewerGdi.GraphRenderer(graph);
        renderer.CalculateLayout();

        int width = 1500;
        Bitmap bitmap = new Bitmap(width, (int)(graph.Height * (width / graph.Width)), PixelFormat.Format32bppPArgb);
        renderer.Render(bitmap);
        bitmap.Save("c:\\temp\\test.png");

Start with the sample code in the issue, especially the BoundaryCurve assignment and the later GraphRenderer.CalculateLayout call. Run the example and inspect whether the explicit label and node dimensions survive layout; done means the rendered node reflects the requested size or the issue explains which step overrides it.