Dart APIunself_appAnalyticRouteObserveranalytic analytic property Null safety AnalyticService analytic final Implementation final AnalyticService analytic; unself_app unself_app AnalyticRouteObserver analytic property AnalyticRouteObserver class Constructors AnalyticRouteObserver Properties analytic hashCode nameExtractor navigator routeFilter runtimeType Methods debugObservingRoute didPop didPush didRemove didReplace didStartUserGesture didStopUserGesture noSuchMethod subscribe toString unsubscribe Operators operator == Static methods defaultNameExtractor defaultRouteFilter