order property
Order is the order this cart became, once checkout completed it. Empty until then, and its presence is what makes a cart final.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? order;