code: public function getShopIdentifiers(array $variation)
      {
          $identifiers = [];
  
          foreach ((array) $variation['variationClients'] as $client) {
              $identity = $this->identityService->findOneBy([
                  'adapterIdentifier' => $client['plentyId'],
                  'adapterName' => PlentymarketsAdapter::NAME,
                  'objectType' => Shop::TYPE,
              ]);
  
              if (null === $identity) {
                  $this->logger->notice('shop not found', $client);
  
                  continue;
              }
  
              $isMappedIdentity = $this->identityService->isMappedIdentity(
                  $identity->getObjectIdentifier(),
                  $identity->getObjectType(),
                  $identity->getAdapterName()
              );
  
              if (!$isMappedIdentity) {
                  continue;
              }
  
              $identifiers[] = $identity->getObjectIdentifier();
          }
  
          return $identifiers;
      }
docs: @param array $variation
  
  @return array