code: func (k *Kademlia) AddrCountC() <-chan int {
  	k.lock.Lock()
  	defer k.lock.Unlock()
  
  	if k.addrCountC == nil {
  		k.addrCountC = make(chan int)
  	}
  	return k.addrCountC
  }
docs: // AddrCountC returns the channel that sends a new
  // address count value on each change.
  // Not receiving from the returned channel will block Register function
  // when address count value changes.