public static void CenterOnVertexControl(this ZoomControl zoomControl, VertexControl vertex)
{
var vPos = vertex.GetPosition();
var width = zoomControl.ActualWidth / zoomControl.Zoom;
var height = zoomControl.ActualHeight / zoomControl.Zoom;
var x = vPos.X - width / 2 + vertex.RenderSize.Width / 2;;
var y = vPos.Y - height / 2 + vertex.RenderSize.Height / 2;
zoomControl.ZoomToContent(new Rect(x, y, width, height));
}