public static function tably($records)
    {
        if (count($records) === 0) {
            return null;
        }
        
        $htmls = array();
        $htmls[] = '<table>';
        foreach ($records as $record) {
            $htmls[] = '<tr>';
            foreach ($record as $k => $v) {
                $htmls[] = sprintf('<td class="%s">%s</td>', Str::machine($k), $v);
            }
            $htmls[] = '</tr>';
        }
        $htmls[] = '</table>';
        return join("\n", $htmls);
    }