public async Task <SheetFile> Handle(ExportSheetQuery request, CancellationToken cancellationToken)
        {
            var shipping = await repository.FindAsync(request.ShippingMethodName);

            return(await sheetWriter.WriteRulesAsync(shipping.HasValue
                                                     ?shipping.Value : new ShippingMethod(request.ShippingMethodName, Array.Empty <ShippingRule>())));
        }