private static List <InvoiceAttachment> ProcessAttachments(int id, List <InvoiceAttachment> attachments)
        {
            var folderPath = ImageFunctions.CreateFolder(id);

            //list to store new file names
            var attachmentImages = new List <InvoiceAttachment>();

            foreach (var remoteFilePath in attachments)
            {
                attachmentImages.AddRange(ConvertAttachments(remoteFilePath.DocumentPath, folderPath));
            }
            return(attachmentImages);
        }