public ActionResult Index(ServerFilesModel model)
        {
            var path = StorageMock.GetSampleDocPath(model.ChosenFileId);

            // Copy file to the App_Data folder, where the upload files is stored.
            string fileId;

            using (var inStream = StorageMock.OpenRead(path)) {
                fileId = StorageMock.Store(inStream, ".pdf");
            }

            if (model.IsCmsCoSign)
            {
                return(RedirectToAction("Index", model.ReturnController, new { cmsfile = fileId }));
            }

            return(RedirectToAction("Index", model.ReturnController, new { userfile = fileId }));
        }