toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (offerId != null) 'offerId': offerId!,
if (purchaseOptionId != null) 'purchaseOptionId': purchaseOptionId!,
if (quantity != null) 'quantity': quantity!,
if (rentalDetails != null) 'rentalDetails': rentalDetails!,
};