code: private function getLanguageIdentifier(array $entry)
      {
          /**
           * @var Repository $shopRepository
           */
          $shopRepository = $this->entityManager->getRepository(ShopModel::class);
  
          /**
           * @var null|ShopModel $customerShop
           */
          $customerShop = $shopRepository->find($entry['languageId']);
  
          if (null === $customerShop) {
              return null;
          }
  
          $languageIdentifier = $this->getIdentifier((string) $customerShop->getLocale()->getId(), Language::TYPE);
  
          if (null === $languageIdentifier) {
              return null;
          }
  
          return $languageIdentifier;
      }
docs: @param array $entry
  
  @return null|string