protected function buildSymfonyMatcher()
    {
        if (!$this->locator) {
            throw new \InvalidArgumentException('Unable to build Symfony matcher without config locator.');
        }

        $yaml_loader = new YamlFileLoader($this->locator);
        $routes = $yaml_loader->load($this->getRoutingFilename());
        $matcher = new UrlMatcher($routes, $this->getRequestContext());

        return($matcher);
    }