public static function cssStringToArray($css)
    {
        $statements = explode(';', preg_replace('/\s+/s', ' ', $css));
        $styles = array();
        foreach ($statements as $statement) {
            $statement = trim($statement);
            if ('' === $statement) {
                continue;
            }
            $p = strpos($statement, ':');
            if ($p <= 0) {
                continue;
            } // invalid statement, just ignore it
            $key = trim(substr($statement, 0, $p));
            $value = trim(substr($statement, $p + 1));
            $styles[$key] = $value;
        }
        return $styles;
    }