public void TestLayers()
{
var writer = new SVGWriter();
writer.StartNewLayer("layer-0");
writer.AddLine(new Segment2d(Vector2d.Zero, Vector2d.AxisX));
writer.StartNewLayer("layer-1");
writer.AddLine(new Segment2d(Vector2d.Zero, Vector2d.AxisY));
writer.Write("layers.svg");
}