public function findChildByRouteName($routeName)
    {
        if ($this->hasChildren()) {
            if (array_key_exists($routeName, $this->children)) {
                return $this->children[$routeName];
            }
            /** @var RouteDefinition $definition */
            foreach ($this->children as $definition) {
                if (null !== $child = $definition->findChildByRouteName($routeName)) {
                    return $child;
                }
            }
        }
        return null;
    }