AppendDomainEventsToStoreMiddleware initializes CollectInMemoryDomainEventsSubscriber, required by DomainEventsPublicationMiddleware:
$collectDomainEventsSubscriber = new CollectInMemoryDomainEventsSubscriber();
DomainEventPublisher::instance()->subscribe($collectDomainEventsSubscriber);
AppendDomainEventsToStoreMiddlewareinitializesCollectInMemoryDomainEventsSubscriber, required byDomainEventsPublicationMiddleware: