traceId property
TraceID is the trace this run IS, so the record and its spans are one thing to move between: it opens the waterfall for THIS run rather than a search that lands near it. Empty when the process had no tracer, never a fabricated 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? traceId;