iTextSharp.text.pdf.PdfReader.RemoveUsageRights C# (CSharp) Метод

        public void RemoveUsageRights() {
            PdfDictionary perms = catalog.GetAsDict(PdfName.PERMS);
            if (perms == null)
                return;
            perms.Remove(PdfName.UR);
            perms.Remove(PdfName.UR3);
            if (perms.Size == 0)
                catalog.Remove(PdfName.PERMS);
        }

// ---------------------------------------------------------------------------
    public byte[] ManipulatePdf(String src, bool remove, bool preserve) {
      PdfReader reader = new PdfReader(src);
      if (remove) reader.RemoveUsageRights();
      using (MemoryStream ms = new MemoryStream()) {
        if (preserve) {
          using (PdfStamper stamper = new PdfStamper(reader, ms, '\0', true)) {
            SetFields(stamper);
          }
        } 
        else {
          using (PdfStamper stamper = new PdfStamper(reader, ms)) {
            SetFields(stamper);
          }
        }
        return ms.ToArray();
      }
    }