Dart APIunself_modelActivityupdated updated property Null safety @JsonDateTime() DateTime updated inherited Implementation @JsonDateTime() DateTime get updated => throw _privateConstructorUsedError; unself_model unself_model Activity updated property Activity class Constructors Activity fromJson Properties accountId appId archiveId copyWith created extra hashCode id labels name runtimeType source sourceId targetId timestamp type updated Methods noSuchMethod toJson toString Operators operator ==