id property
ID is the caller's own stable identifier for the event. It selects the below-the-line review sample by hash, so a counter would make the sample steerable — use the id the event already has.
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;