code: public function prePersist(LifecycleEventArgs $args)
      {
          $entity = $args->getEntity();
  
          if (!$entity instanceof Identitiable) {
              return;
          }
  
          $this->identityService->generateIdentity($entity);
      }
docs: Assign the current session identity, if none provided
  
  @param \Doctrine\ORM\Event\LifecycleEventArgs $args