Nord\Lumen\Cors\CorsService::validatePreflightRequest PHP Метод

    protected function validatePreflightRequest(Request $request)
    {
        $origin = $request->headers->get('Origin');
        if (!$this->isOriginAllowed($origin)) {
            throw new HttpResponseException($this->createOriginNotAllowedResponse($request));
        }
        $method = $request->headers->get('Access-Control-Request-Method');
        if ($method && !$this->isMethodAllowed($method)) {
            throw new HttpResponseException($this->createMethodNotAllowedResponse($request));
        }
        if (!$this->isAllHeadersAllowed()) {
            $headers = $request->headers->get('Access-Control-Request-Headers');
            if (is_string($headers)) {
                foreach (explode(', ', $headers) as $header) {
                    if (!$this->isHeaderAllowed($header)) {
                        throw new HttpResponseException($this->createHeaderNotAllowedResponse($request));
                    }
                }
            }
        }
    }