protected function negotiateVCard($input, &$mimeType = null)
    {
        $result = HTTP\negotiateContentType(
            $input,
            [
                // Most often used mime-type. Version 3
                'text/x-vcard',
                // The correct standard mime-type. Defaults to version 3 as
                // well.
                'text/vcard',
                // vCard 4
                'text/vcard; version=4.0',
                // vCard 3
                'text/vcard; version=3.0',
                // jCard
                'application/vcard+json',
            ]
        );

        $mimeType = $result;
        switch ($result) {
            default:
            case 'text/x-vcard':
            case 'text/vcard':
            case 'text/vcard; version=3.0':
                $mimeType = 'text/vcard';

                return 'vcard3';
            case 'text/vcard; version=4.0':
                return 'vcard4';
            case 'application/vcard+json':
                return 'jcard';

        // @codeCoverageIgnoreStart
        }
        // @codeCoverageIgnoreEnd
    }