Dart APIunself_appAnalyticRouteObserverrouteFilter routeFilter property Null safety RouteFilter routeFilter final Implementation final RouteFilter routeFilter; unself_app unself_app AnalyticRouteObserver routeFilter 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