public IEnumerable <string> GetBookmarkNames(int id)
        {
            var undFormVersion = _context.UndFormVersion.Find(id);
            var getFilePath    = undFormVersion.FileName.ToString();

            //string newFileName = "EndrosementBlankPreview.pdf";

            Document           endorsement = new Document(getFilePath);
            DocumentBuilder    builder     = new DocumentBuilder(endorsement);
            BookmarkCollection bookmarks   = endorsement.Range.Bookmarks;

            var bookmarkNames = bookmarks.Select(b => b.Name);

            return(bookmarkNames);
        }