How can I make a line two lines?

Document doc = new Document();
Page page = doc.Pages.Add();
page.PageInfo.Margin = new MarginInfo(0, 0, 0, 0);

Line topLine = new Line(new float[]{ 10, page.PageInfo.Height - 10, page.PageInfo.Width - 10, page.PageInfo.Height - 10 });

topLine.GraphInfo.IsDoubled= true;

Graph graph = new Graph((float)page.PageInfo.Width, (float)page.PageInfo.Height);
graph.Shapes.Add(topLine);
page.Paragraphs.Add(graph);

But only one line comes out.
How do I make two lines?

@Junyoung

Thank you for contacting support.

We have worked with the code snippet shared by you and have been able to reproduce the problem. A ticket with ID PDFNET-45079 has been logged in our issue management system for further investigation and resolution. The ticket ID has been linked with this thread so that you will receive notification as soon as the ticket is resolved.

We are sorry for the inconvenience.

The issues you have found earlier (filed as PDFNET-45079) have been fixed in Aspose.PDF for .NET 19.7.