public function split($chunkSize = 1)
    {
        if (!$this->isNumber($chunkSize)) {
            throw new StringObjectException(StringObjectException::MSG_INVALID_ARG, [
                '$chunkSize',
                'integer'
            ]);
        }

        $arr = str_split($this->val(), $chunkSize);

        return new ArrayObject($arr);
    }