public function setMaxFilesize($maxFilesize = 'auto')
    {
        switch ($maxFilesize) {
            case 'auto':
                $maxFilesize = $this->convertToBytes(
                    ini_get('upload_max_filesize')
                );
                break;
        }

        $this->maxFilesize = $maxFilesize;
        $this->setAttribute('filesize', $maxFilesize);
    }