Товарищи, объясните пожалуйста что делает этот код:
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Class XXX {
    public static function create(
        ?ResponseFactoryInterface $responseFactory = null,
        ?ContainerInterface $container = null,
        ?CallableResolverInterface $callableResolver = null,
        ?RouteCollectorInterface $routeCollector = null,
        ?RouteResolverInterface $routeResolver = null,
        ?MiddlewareDispatcherInterface $middlewareDispatcher = null
    ): App {
        static::$responseFactory = $responseFactory ?? static::$responseFactory;
        return new App(
            self::determineResponseFactory(),
            $container ?? static::$container,
            $callableResolver ?? static::$callableResolver,
            $routeCollector ?? static::$routeCollector,
            $routeResolver ?? static::$routeResolver,
            $middlewareDispatcher ?? static::$middlewareDispatcher
        );
    }
}

XXX::create();