actor property
Actor is the email of the principal who made the change. Empty for a write by an in-process composer; a project key can never appear here, because evaluating flags is all a key may do.
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? actor;