static private function curl($method, $url, $data, $special_options = null)
    {
        $curl = \curl_init();

        if ($method == 'GET') {
            if (!empty($data)) {
                $url .= '?' . \http_build_query($data);
            }
        } elseif (!is_null($special_options)) {
            \curl_setopt_array($curl, $special_options);
            \curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $method);
            \curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
        } else {
            \curl_setopt($curl, CURLOPT_CUSTOMREQUEST, $method);
            \curl_setopt($curl, CURLOPT_POSTFIELDS, \http_build_query($data));
        }

        \curl_setopt($curl, CURLOPT_URL, $url);

        \curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, 0);
        \curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
        \curl_setopt($curl, CURLOPT_CONNECTTIMEOUT, 10);
        \curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);

        $content = \curl_exec($curl);
        \curl_close($curl);

        return $content;
    }