code: func (rt *routingTable) GetNeighbors(id *bitmap, size int) []*node {
  	rt.RLock()
  	nodes := make([]interface{}, 0, rt.cachedNodes.Len())
  	for item := range rt.cachedNodes.Iter() {
  		nodes = append(nodes, item.val.(*node))
  	}
  	rt.RUnlock()
  
  	neighbors := getTopK(nodes, id, size)
  	result := make([]*node, len(neighbors))
  
  	for i, nd := range neighbors {
  		result[i] = nd.(*node)
  	}
  	return result
  }
docs: // GetNeighbors returns the size-length nodes closest to id.