PDF Mosaic: How to add rubber stamp annotation to PDF documents

using PDFMosaic;
using System;
 
namespace PDFRubberStampAnnotationSample
{
    class PDFRubberStamptAnnotationSample
    {
        static void Main()
        {
            PDFDocument pdf = new PDFDocument();
            pdf.Pages.Add(new PDFPage(PDFPaperFormat.A4));
            PDFRubberStampAnnotation annot = new PDFRubberStampAnnotation(100, 50, 75, 50);
            annot.Contents = "PDF rubber stamp annotation";
            annot.Color = new PDFColorRGB(80, 0, 150);
 
            pdf.Pages[0].Annotations.Add(annot);
            pdf.Save("TestRubberStamp.pdf", true);
        }
    }
}