public async Task <IActionResult> PutUser(int id, User user)
        {
            if (id != user.Id)
            {
                return(BadRequest());
            }

            _context.Entry(user).State = EntityState.Modified;

            try
            {
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!UserExists(id))
                {
                    return(NotFound());
                }
                else
                {
                    throw;
                }
            }

            return(NoContent());
        }
        private async void RecalcRequestTotal(int requestId)
        {
            var request = _context.Request.Find(requestId);

            request.Total = _context.RequestLine.Include(l => l.Product)
                            .Where(l => l.RequestId == requestId)
                            .Sum(l => l.Quantity * l.Product.Price);
//            request.Total = request.RequestLines.Sum(x => x.Quantity * x.Product.Price);
            await _context.SaveChangesAsync();
        }