public static function normalizeHeader($name) {
        static $special = [
            'etag' => 'ETag', 'p3p' => 'P3P', 'www-authenticate' => 'WWW-Authenticate',
            'x-ua-compatible' => 'X-UA-Compatible'
        ];

        $name = str_replace(['-', '_'], ' ', strtolower($name));
        if (isset($special[$name])) {
            $name = $special[$name];
        } else {
            $name = str_replace(' ', '-', ucwords($name));
        }
        return $name;
    }