为什么没做 url rewrite 但是效果却和做了一样？

require '../vendor/autoload.php';
define("WWW_PATH", dirname(realpath(__FILE__)));
define("ROOT_PATH", dirname(WWW_PATH));

$app = new \Slim\App();

$app->group('/utils', function () use ($app) {
    $app->get('/date', function ($request, $response) {
        return $response->getBody()->write(date('Y-m-d H:i:s'));
    });
    $app->get('/time', function ($request, $response) {
        return $response->getBody()->write(time());
    });
})->add(function ($request, $response, $next) {
    $response->getBody()->write('It is now ');
    $response = $next($request, $response);
    $response->getBody()->write('. Enjoy!');

    return $response;
});

$app->run();