code: function addBusinessWorker() {
          $this->_business_worker = new BusinessWorker;
          $this->_business_worker->onWorkerStart = [$this, 'onBusinessStart'];
          $this->_business_worker->onWorkerStop = [$this, 'onBusinessStop'];
          $this->_business_worker->eventHandler = $this;
          $this->businessWorkerConfig(DEFAULT_BUSINESS_WORKER_CONFIG);
      }
docs: 单独添加BusinessWorker