getGetterSetterMap method
Implemented by subclasses to map the getters and setters of the object.
Cannot have keys that have the values TYPE or ID
Implementation
@override
Map<String, Tuple2<Getter, Setter>> getGetterSetterMap() => {
"collectionId": Tuple2(() => collectionId, (val) => collectionId = val),
"lastUpdated": GenericModel.dateTime(
() => lastUpdated, (value) => lastUpdated = value),
};