Psr7Middlewares\Middleware\Robots::__invoke PHP Метод

    public function __invoke(RequestInterface $request, ResponseInterface $response, callable $next)
    {
        if ($request->getUri()->getPath() === '/robots.txt') {
            $response = $response->withHeader('Content-Type', 'text/plain');
            if ($this->allow) {
                $response->getBody()->write("User-Agent: *\nAllow: /");
                return $response;
            }
            $response->getBody()->write("User-Agent: *\nDisallow: /");
            return $response;
        }
        $response = $next($request, $response);
        if ($this->allow) {
            return $response->withHeader(self::HEADER, 'index, follow');
        }
        return $response->withHeader(self::HEADER, 'noindex, nofollow, noarchive');
    }