finalizeRoute method

void finalizeRoute (Route route)

Complete the lifecycle for a route that has been popped off the navigator.

When the navigator pops a route, the navigator retains a reference to the route in order to call Route.dispose if the navigator itself is removed from the tree. When the route is finished with any exit animation, the route should call this function to complete its lifecycle (e.g., to receive a call to Route.dispose).

The given route must have already received a call to Route.didPop. This function may be called directly from Route.didPop if Route.didPop will return true.

Implementation 

void finalizeRoute(Route<dynamic> route) {
  _poppedRoutes.remove(route);
  route.dispose();
}