code: public function saveReview()
      {
          if (!$this->validateOptIn()) {
              \OxidEsales\Eshop\Core\Registry::get(\OxidEsales\Eshop\Core\UtilsView::class)->addErrorToDisplay('OEGDPROPTIN_REVIEW_FORM_ERROR_MESSAGE');
              return false;
          }
  
          return parent::saveReview();
      }
docs: Saves user ratings and review text (oxReview object)
  
  @return null