code: func (s *GlobalStore) nodeIndex(addr common.Address) (index int, found bool) {
  	l := len(s.nodes)
  	index = sort.Search(l, func(i int) bool {
  		return bytes.Compare(s.nodes[i][:], addr[:]) >= 0
  	})
  	found = index < l && bytes.Equal(s.nodes[index][:], addr[:])
  	return index, found
  }
docs: // nodeIndex returns the index of a node address in nodes slice.