code: func (r *Reflector) LastSyncResourceVersion() string {
  	r.lastSyncResourceVersionMutex.RLock()
  	defer r.lastSyncResourceVersionMutex.RUnlock()
  	return r.lastSyncResourceVersion
  }
docs: // LastSyncResourceVersion is the resource version observed when last sync with the underlying store
  // The value returned is not synchronized with access to the underlying store and is not thread-safe