code: func (lb *LogBroker) Stop() error {
  	lb.mu.Lock()
  	defer lb.mu.Unlock()
  
  	if lb.cancelAll == nil {
  		return errNotRunning
  	}
  	lb.cancelAll()
  	lb.cancelAll = nil
  
  	lb.logQueue.Close()
  	lb.subscriptionQueue.Close()
  
  	return nil
  }
docs: // Stop stops the log broker