public async Task <ServiceResult <ProductRequestViewModel> > GetSingle(int id)
        {
            var model = await _repository.GetSingleAsync(id);

            if (model == null)
            {
                return(ServiceResultFactory.Success <ProductRequestViewModel>(null));
            }

            var viewModel = new ProductRequestViewModel
            {
                ProductName       = model.Name,
                Code              = model.Code,
                EanCode           = model.EanCode,
                ProductGroupId    = model.ProductCategoryId,
                Description       = model.Description,
                SellingPriceBruto = model.Price,
                VatPercent        = model.Vat,
                Type              = model.ProductType,
                Unit              = model.Unit,
                UseProductVat     = model.UseProductVat
            };

            return(ServiceResultFactory.Success(viewModel));
        }