routeInformationProvider property Null safety
The route information provider for the router.
The value at the time of first build will be used as the initial route. The Router listens to this provider and rebuilds with new names when it notifies.
This can be null if this router does not rely on the route information to build its content. In such case, the routeInformationParser must also be null.
final RouteInformationProvider? routeInformationProvider;