iTextSharp.text.pdf.PdfCopy.PageStamp.AddAnnotation C# (CSharp) Метод

            public void AddAnnotation(PdfAnnotation annot)
            {
                List<PdfAnnotation> allAnnots = new List<PdfAnnotation>();
                if (annot.IsForm()) {
                    PdfFormField field = (PdfFormField)annot;
                    if (field.Parent != null)
                        return;
                    ExpandFields(field, allAnnots);
                    if (cstp.fieldTemplates == null)
                        cstp.fieldTemplates = new Dictionary<PdfTemplate,object>();
                }
                else
                    allAnnots.Add(annot);
                for (int k = 0; k < allAnnots.Count; ++k) {
                    annot = allAnnots[k];
                    if (annot.IsForm()) {
                        if (!annot.IsUsed()) {
                            Dictionary<PdfTemplate,object> templates = annot.Templates;
                            if (templates != null) {
                                foreach (PdfTemplate tpl in templates.Keys) {
                                    cstp.fieldTemplates[tpl] = null;
                                }
                            }
                        }
                        PdfFormField field = (PdfFormField)annot;
                        if (field.Parent == null)
                            AddDocumentField(field.IndirectReference);
                    }
                    if (annot.IsAnnotation()) {
                        PdfObject pdfobj = PdfReader.GetPdfObject(pageN.Get(PdfName.ANNOTS), pageN);
                        PdfArray annots = null;
                        if (pdfobj == null || !pdfobj.IsArray()) {
                            annots = new PdfArray();
                            pageN.Put(PdfName.ANNOTS, annots);
                        }
                        else
                            annots = (PdfArray)pdfobj;
                        annots.Add(annot.IndirectReference);
                        if (!annot.IsUsed()) {
                            PdfRectangle rect = (PdfRectangle)annot.Get(PdfName.RECT);
                            if (rect != null && (rect.Left != 0 || rect.Right != 0 || rect.Top != 0 || rect.Bottom != 0)) {
                                int rotation = reader.GetPageRotation(pageN);
                                Rectangle pageSize = reader.GetPageSizeWithRotation(pageN);
                                switch (rotation) {
                                    case 90:
                                        annot.Put(PdfName.RECT, new PdfRectangle(
                                            pageSize.Top - rect.Bottom,
                                            rect.Left,
                                            pageSize.Top - rect.Top,
                                            rect.Right));
                                        break;
                                    case 180:
                                        annot.Put(PdfName.RECT, new PdfRectangle(
                                            pageSize.Right - rect.Left,
                                            pageSize.Top - rect.Bottom,
                                            pageSize.Right - rect.Right,
                                            pageSize.Top - rect.Top));
                                        break;
                                    case 270:
                                        annot.Put(PdfName.RECT, new PdfRectangle(
                                            rect.Bottom,
                                            pageSize.Right - rect.Left,
                                            rect.Top,
                                            pageSize.Right - rect.Right));
                                        break;
                                }
                            }
                        }
                    }
                    if (!annot.IsUsed()) {
                        annot.SetUsed();
                        cstp.AddToBody(annot, annot.IndirectReference);
                    }
                }
            }