public async Task <IActionResult> Put([FromBody] BillViewModel bill)
        {
            if (ModelState.IsValid)
            {
                var thisBill = Mapper.Map <Bill>(bill);
                thisBill.UserId = new Guid(_userManager.GetUserId(HttpContext.User));
                _repository.UpdateBill(thisBill);

                if (await _repository.SaveChangesAsync())
                {
                    return(Created($"api/bills/{thisBill.Id}", Mapper.Map <BillViewModel>(thisBill)));
                }
            }
            return(BadRequest("Failed to save the bill"));
        }