// When the user selects a shipping rate, set that rate on the checkout and proceed to the discount activity.
        private async Task OnShippingRateSelectedAsync(ShippingRate shippingRate)
        {
            ShowLoadingDialog(Resource.String.syncing_data);

            try
            {
                await SampleApplication.SetShippingRateAsync(shippingRate);

                DismissLoadingDialog();
                StartActivity(new Intent(this, typeof(DiscountActivity)));
            }
            catch (ShopifyException ex)
            {
                OnError(ex.Error);
            }
        }