public async Task SendConfirmationEmails(SheetUpload sheetUpload)
        {
            var recipients = new List <EmailAddress>();

            var tasks = new List <Task>();

            foreach (Person person in sheetUpload.People)
            {
                foreach (var email in person.Emails)
                {
                    await sendConfirmationEmail(email.EmailAddress, person.FirstName, person.Id);
                }
            }
        }
        public SheetUpload toSheetUpload(IFormFile file, string userId)
        {
            if (file == null)
            {
                throw new ArgumentNullException("file", "Argument file cannot be null.");
            }

            MemoryStream memoryStream = new MemoryStream();

            file.CopyTo(memoryStream);

            var people = convertToPersonCollection(memoryStream);

            SheetUpload upload = new SheetUpload(userId, file.FileName);

            upload.People = people;
            return(upload);
        }