private function setRealFileName($value) {
        $base64FileNamePos = strpos($value, 'filename ');
        if (is_int($base64FileNamePos) && $base64FileNamePos >= 0) {
            $value = substr($value, $base64FileNamePos + 9); // 9 - length of 'filename '
            $this->realFileName = base64_decode($value);
        } else {
            $this->realFileName = $value;
        }
        return $this;
    }