composition

type Services struct {
	SubscriptionsRegistry *subscription.Registry
	RemoveSubscriptions   *sub_service.RemoveSubscriptionsService
}

type UseCases struct {
	Publish     publish.PublishMessage
	Subscribe   subscribe.SubscribeChannel
	ReceiveData data.ReceiveData
	Unsubscribe unsubscribe.UnsubscribeChannel
	Shutdown    shutdown.ShutdownConnection
}