id property
ID names the row forever. It is DERIVED from the row's own subject and instant, not allocated, so two materialisations of the same fact agree on it without coordinating.
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? id;