code: public function postFlush(PostFlushEventArgs $args)
      {
          $maps = $args->getEntityManager()->getUnitOfWork()->getIdentityMap();
  
          foreach ($maps as $entities) {
              foreach ($entities as $entity) {
                  if (!$entity instanceof Parameter) {
                      continue;
                  }
  
                  $entity->setValue(unserialize($entity->getValue()));
              }
          }
      }
docs: Unserialize parameter entity value property after saving from storage.
  
  @param \Doctrine\ORM\Event\PostFlushEventArgs $args