public function getPlatformVersion($returnVersionNumbers = false, $returnServerFlavor = false)
    {
        if ($this->_platformVersion == self::PLATFORM_VERSION_UNKNOWN || $this->_platformVersion == '') {
            return self::PLATFORM_VERSION_UNKNOWN;
        }

        if ($returnVersionNumbers) {
            return $this->_platformVersion;
        } else {
            switch ($this->getPlatform()) {
                case self::PLATFORM_WINDOWS:
                    if (substr($this->_platformVersion, 0, 3) == 'NT ') {
                        return $this->windowsNTVerToStr(substr($this->_platformVersion, 3), $returnServerFlavor);
                    } else {
                        return $this->windowsVerToStr($this->_platformVersion);
                    }
                    break;

                case self::PLATFORM_MACINTOSH:
                    return $this->macVerToStr($this->_platformVersion);

                case self::PLATFORM_ANDROID:
                    return $this->androidVerToStr($this->_platformVersion);

                case self::PLATFORM_IOS:
                    return $this->iOSVerToStr($this->_platformVersion);

                default: return self::PLATFORM_VERSION_UNKNOWN;
            }
        }
    }