protected function _checkUserAgent($sAgent, $sExistingAgent)
    {
        $blCheck = false;
        // processing
        $oUtils = \OxidEsales\Eshop\Core\Registry::getUtilsServer();
        $sAgent = $oUtils->processUserAgentInfo($sAgent);
        $sExistingAgent = $oUtils->processUserAgentInfo($sExistingAgent);

        if ($sAgent && $sAgent !== $sExistingAgent) {
            if ($sExistingAgent) {
                $this->_sErrorMsg = "Different browser ({$sExistingAgent}, {$sAgent}), creating new SID...<br>";
            }
            $blCheck = true;
        }

        return $blCheck;
    }