code: public void findRouteWith(NavigationRoute.Builder builder) {
      if (builder != null) {
        navigationRoute = builder.build();
        navigationRoute.getRoute(directionsResponseCallback);
      }
    }
docs: Executes the given NavigationRoute builder, eventually triggering
  any {@link RouteListener} that has been added via {@link RouteFetcher#addRouteListener(RouteListener)}.
  
  @param builder to be executed