code: func (ps *peerSet) AllPeerIDs() []string {
  	ps.lock.RLock()
  	defer ps.lock.RUnlock()
  
  	res := make([]string, len(ps.peers))
  	idx := 0
  	for id := range ps.peers {
  		res[idx] = id
  		idx++
  	}
  	return res
  }
docs: // AllPeerIDs returns a list of all registered peer IDs