code: private function getAttributes(array $product)
      {
          $attributes = [];
  
          for ($i = 0; $i < 20; ++$i) {
              $key = 'free' . ($i + 1);
  
              if (!array_key_exists($key, $product)) {
                  continue;
              }
  
              $attributes[] = Attribute::fromArray([
                  'key' => $key,
                  'value' => (string) $product[$key],
              ]);
          }
  
          $attributes[] = $this->getShortDescriptionAsAttribute($product);
          $attributes[] = $this->getTechnicalDataAsAttribute($product);
          $attributes[] = $this->getAgeRestrictionAsAttribute($product);
          $attributes[] = $this->getSecondProductNameAsAttribute($product);
          $attributes[] = $this->getThirdProductNameAsAttribute($product);
          $attributes[] = $this->getItemIdAsAttribute($product);
  
          return $attributes;
      }
docs: @param array $product
  
  @return Attribute[]