code: public function remind(string $providerName, ?\DateTimeImmutable $now = null): void
      {
          $now = $now ?? new \DateTimeImmutable();
  
          /** @var ProviderInterface $provider */
          $provider = $this->providers->get($providerName);
  
          /** @var ItemInterface $item */
          foreach ($provider->getItems($now) as $item) {
              $markerId = $providerName.':'.$item->getId();
  
              if ($this->marker->isMarked($markerId)) {
                  continue;
              }
  
              $event = new ReminderEvent($providerName, $now, $item);
              $this->dispatcher->dispatch(ReminderEvents::remind($providerName), $event);
  
              $this->marker->mark($markerId);
  
              if ($item instanceof ClearableItemInterface) {
                  $item->clear();
              }
          }
      }
docs: {@inheritdoc}