public function getLanguage()
    {
        /** @var Session $oSession */
        $oSession = $this->getInstance("Session");
        /** @var Utilities $oUtils */
        $oUtils = $this->getInstance("Utilities");

        $iLanguage = $oUtils->getRequestVar("setup_lang", "post");

        if (isset($iLanguage)) {
            $oSession->setSessionParam('setup_lang', $iLanguage);
            $iLanguageSubmit = $oUtils->getRequestVar("setup_lang_submit", "post");
            if (isset($iLanguageSubmit)) {
                //updating setup language, so disabling redirect to next step, just reloading same step
                $_GET['istep'] = $_POST['istep'] = $this->getInstance("Setup")->getStep('STEP_WELCOME');
            }
        } elseif ($oSession->getSessionParam('setup_lang') === null) {
            $aLangs = ['en', 'de'];
            $sBrowserLang = strtolower(substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2));
            $sBrowserLang = (in_array($sBrowserLang, $aLangs)) ? $sBrowserLang : $aLangs[0];
            $oSession->setSessionParam('setup_lang', $sBrowserLang);
        }

        return $oSession->getSessionParam('setup_lang');
    }