code: func (h *Hive) savePeers() error {
  	var peers []*BzzAddr
  	h.Kademlia.EachAddr(nil, 256, func(pa *BzzAddr, i int) bool {
  		if pa == nil {
  			log.Warn(fmt.Sprintf("empty addr: %v", i))
  			return true
  		}
  		log.Trace("saving peer", "peer", pa)
  		peers = append(peers, pa)
  		return true
  	})
  	if err := h.Store.Put("peers", peers); err != nil {
  		return fmt.Errorf("could not save peers: %v", err)
  	}
  	return nil
  }
docs: // savePeers, savePeer implement persistence callback/