id property
ID is the winning assertion's content digest, so this answer traces to the exact record it came from — and that record can be placed under litigation hold by naming this id.
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;