DirectoryInfo di = new DirectoryInfo(@"E:\Temp\1\Patriotic_Menu_1Sided");
            FileInfo[] imageFiles = di.GetFiles("*.jpg");

            var imgFile = imageFiles.FirstOrDefault();
            Blob uploadedFileBlob = new Blob(imgFile.Name, imgFile);


            var document = (Document)client.Operation("FileManager.Import")
                                .SetInput(uploadedFileBlob)
                                .SetContext("currentDocument", "/default-domain/workspaces/POC/")
                                .Execute()
                                .Result;

            FileInfo[] otherFiles = di.GetFiles("*.*");
            otherFiles = otherFiles.Where(file => file.Extension != ".jpg" && file.Extension != ".zip").ToArray();
            if (otherFiles.Count() > 0)
            {
                BlobList blobs = new BlobList();
                foreach (var file in otherFiles)
                    blobs.Add(new Blob(file.Name, file));


                var attachedDocuments = client.Operation("Blob.Attach")
                                 .SetInput(blobs)
                                 .SetParameter("document", document.Path)
                                 .SetParameter("xpath", "files:files")
                                 .Execute()
                                 .Result; //exception occur here


            }