code: public function transform($value)
      {
          $sites = array();
  
          if (!empty($value)) {
              foreach ($value as $associatedSite) {
                  $sites[] = $this->siteRepositoy->findOneBySiteId($associatedSite['siteId']);
              }
          }
  
          return $sites;
      }
docs: @param array $value
  
  @return SiteInterface
  
  @throws TransformationFailedException When the transformation fails.