code: public function routes()
      {
          $routes = array_merge($this->routes, $this->collector->getData());
  
          return function (RouteCollector $collector) use ($routes) {
              foreach (array_filter($routes) as $route) {
                  list($method, $uri, $handler) = (array) $route;
  
                  $collector->addRoute($method, $uri, $handler);
              }
          };
      }
docs: Returns a listing of routes available.
  
  @return callable