code: func (k *Kademlia) NeighbourhoodDepth() (depth int) {
  	k.lock.RLock()
  	defer k.lock.RUnlock()
  	return depthForPot(k.conns, k.NeighbourhoodSize, k.base)
  }
docs: // NeighbourhoodDepth returns the depth for the pot, see depthForPot