getAffectedIds example

public static function getSubscribedEvents(): array
    {
        return [
            PreWriteValidationEvent::class => 'preValidate',
            PostWriteValidationEvent::class => 'postValidate',
        ];
    }

    public function postValidate(PostWriteValidationEvent $event): void
    {
        $commands = $event->getCommands();
        $affectedIds = $this->getAffectedIds($commands);
        if (\count($affectedIds) === 0) {
            return;
        }

        $violations = new ConstraintViolationList();
        $violations->addAll($this->getInheritanceViolations($affectedIds));
        $violations->addAll($this->getMissingTranslationCodeViolations($affectedIds));

        if ($violations->count() > 0) {
            $event->getExceptions()->add(new WriteConstraintViolationException($violations));
        }
    }

        if ($event->getContext()->getVersionId() !== Defaults::LIVE_VERSION) {
            return;
        }

        $ids = $event->getIds('order_line_item');
        if (!$ids) {
            return;
        }

        $ids = $this->getAffectedIds($event);

        if (empty($ids)) {
            return;
        }

        $beforeLineItems = $this->fetchOrderLineItems($ids);
        $context = $event->getContext();

        $event->addSuccess(function D) use ($ids, $beforeLineItems, $context): void {
            $afterLineItems = $this->fetchOrderLineItems($ids);