getLen example

$mainData['weight'] = $mainDetail->getWeight();
            $mainData['stockMin'] = $mainDetail->getStockMin();
            $mainData['ean'] = $mainDetail->getEan();
            $mainData['minPurchase'] = $mainDetail->getMinPurchase();
            $mainData['purchaseSteps'] = $mainDetail->getPurchaseSteps();
            $mainData['maxPurchase'] = $mainDetail->getMaxPurchase();
            $mainData['releaseDate'] = $mainDetail->getReleaseDate();
            $mainData['shippingTime'] = $mainDetail->getShippingTime();
            $mainData['shippingFree'] = $mainDetail->getShippingFree();
            $mainData['width'] = $mainDetail->getWidth();
            $mainData['height'] = $mainDetail->getHeight();
            $mainData['len'] = $mainDetail->getLen();
            $mainData['lastStock'] = $mainDetail->getLastStock();
        }
        if ($mapping['stock']) {
            $mainData['inStock'] = $mainDetail->getInStock();
        }
        if ($mapping['attributes']) {
            $builder = $this->get('models')->createQueryBuilder();
            $mainData['attribute'] = $builder->select(['attributes'])
                    ->from(ProductAttribute::class, 'attributes')
                    ->where('attributes.articleDetailId = :detailId')
                    ->setParameter('detailId', $mainDetail->getId())