private function loadHeaders()
    {
        foreach ($_SERVER as $key => $value) {
            $subset = substr($key, 0, 5);
            if ($subset <> 'HTTP_' && $subset <> 'CONTE') {
                continue;
            }
            $header = str_replace(
                ' ',
                '-',
                ucwords(
                    str_replace(['http_', '_'], ['', ' '], strtolower($key))
                )
            );
            $this->headers[$this->headerKey($header)] = [$value];
        }
    }