code: public function getDocuments()
      {
          return new SyncStorageImportIterator(
              [
                  'sync_storage' => $this->getSyncStorage(),
                  'shop_id' => $this->getShopId(),
                  'document_type' => $this->getDocumentType(),
              ],
              $this->getElasticsearchManager()->getRepository($this->getDocumentClass()),
              $this->getDoctrineManager(),
              $this->getEntityClass()
          );
      }
docs: Gets iterator for all documents which need to be updated.
  
  @return SyncStorageImportIterator