toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (amount != null) 'amount': amount!,
if (fullRefund != null) 'fullRefund': fullRefund!,
if (lineItemId != null) 'lineItemId': lineItemId!,
if (productId != null) 'productId': productId!,
if (quantity != null) 'quantity': quantity!,
};