toJson method
Implementation
@override
Map<String, dynamic> toJson() => <String, dynamic>{
'product_info': productInfo?.toJson(),
'currency': currency,
'total_amount': totalAmount,
'start_parameter': startParameter,
'is_test': isTest,
'need_shipping_address': needShippingAddress,
'receipt_message_id': receiptMessageId,
'paid_media': paidMedia?.toJson(),
'paid_media_caption': paidMediaCaption?.toJson(),
'@type': constructor,
};