private function createCurlHandlerForUrl(URL $url, array &$handlers)
    {
        $handler = curl_init();

        curl_setopt_array($handler, [
            CURLOPT_URL => $url->url,
            CURLOPT_RETURNTRANSFER => false,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_CONNECTTIMEOUT => $this->options['connection_timeout'],
            CURLOPT_TIMEOUT => $this->options['timeout'],
            CURLOPT_FAILONERROR => true,
            CURLOPT_NOBODY => true,
        ]);

        if ($this->options['ignore_certificate']) {
            curl_setopt_array($handler, [
                CURLOPT_SSL_VERIFYPEER => false,
                CURLOPT_SSL_VERIFYHOST => false,
            ]);
        }

        $handlers[(int)$handler] = $url;

        return $handler;
    }