code: public function parse(array $variation)
      {
          $variationIdentity = $this->identityService->findOneBy([
              'adapterIdentifier' => (string) $variation['id'],
              'adapterName' => PlentymarketsAdapter::NAME,
              'objectType' => Variation::TYPE,
          ]);
  
          if (null === $variationIdentity) {
              return null;
          }
  
          $stockIdentity = $this->identityService->findOneOrCreate(
              (string) $variationIdentity->getAdapterIdentifier(),
              PlentymarketsAdapter::NAME,
              Stock::TYPE
          );
  
          $stock = new Stock();
          $stock->setIdentifier($stockIdentity->getObjectIdentifier());
          $stock->setVariationIdentifier($variationIdentity->getObjectIdentifier());
          $stock->setStock($this->getStock($variation));
  
          return $stock;
      }
docs: {@inheritdoc}