code: private function getCustomerGroup(array $entry)
      {
          /**
           * @var EntityRepository $customerGroupRepository
           */
          $customerGroupRepository = $this->entityManager->getRepository(GroupModel::class);
  
          /**
           * @var GroupModel $customerGroup
           */
          return $customerGroupRepository->findOneBy(['key' => $entry['groupKey']]);
      }
docs: @param array $entry
  
  @return null|GroupModel