code: private function getPropertyData(Product $product)
      {
          /**
           * @var EntityRepository $groupRepository
           */
          $groupRepository = $this->entityManager->getRepository(GroupModel::class);
  
          /**
           * @var GroupModel $propertyGroup
           */
          $propertyGroup = $groupRepository->findOneBy(['name' => 'PlentyConnector']);
  
          if (null === $propertyGroup) {
              $propertyGroup = new GroupModel();
              $propertyGroup->setName('PlentyConnector');
              $propertyGroup->setPosition(1);
              $propertyGroup->setComparable(true);
              $propertyGroup->setSortMode(1);
  
              $this->entityManager->persist($propertyGroup);
              $this->entityManager->flush();
              $this->entityManager->clear();
          }
  
          $result = [];
          $result['filterGroupId'] = $propertyGroup->getId();
          $result['propertyValues'] = [];
  
          foreach ($product->getProperties() as $property) {
              foreach ($property->getValues() as $value) {
                  $result['propertyValues'][] = [
                      'option' => [
                          'name' => $property->getName(),
                      ],
                      'value' => $value->getValue(),
                  ];
              }
          }
  
          return $result;
      }
docs: @param Product $product
  
  @return array