protected static function splitFirstLine($firstLine)
    {
        $parts = preg_split('/\\s/', $firstLine, null, PREG_SPLIT_NO_EMPTY);
        if (count($parts) > 1) {
            return $parts;
        }
        $parts = explode(',', $firstLine);
        if (count($parts) > 1) {
            return $parts;
        }

        return preg_split('/(\\d+\\D*)/', $firstLine, null, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
    }