protected function spawnWorker() {
        $workerName = $this->worker;
        
        /** @var \CharlotteDunois\Phoebe\Worker  $worker */
        $worker = new $workerName(...$this->ctor);
        $this->messenger->prepareWorker($worker);
        
        $worker->start(static::WORKER_START_OPTIONS);
        $this->workers[$worker->id] = $worker;
        
        return $worker;
    }