code: func (c *controller) cleanupServiceDiscovery(cleanupNID string) {
  	c.Lock()
  	defer c.Unlock()
  	if cleanupNID == "" {
  		logrus.Debugf("cleanupServiceDiscovery for all networks")
  		c.svcRecords = make(map[string]svcInfo)
  		return
  	}
  	logrus.Debugf("cleanupServiceDiscovery for network:%s", cleanupNID)
  	delete(c.svcRecords, cleanupNID)
  }
docs: // cleanupServiceDiscovery when the network is being deleted, erase all the associated service discovery records