toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (lineItems != null) 'lineItems': lineItems!,
if (operationId != null) 'operationId': operationId!,
if (orderId != null) 'orderId': orderId!,
if (returnMethodType != null) 'returnMethodType': returnMethodType!,
};