code: func (entries Entries) search(key uint64) int {
  	return sort.Search(len(entries), func(i int) bool {
  		return entries[i].Key() >= key
  	})
  }
docs: // search will perform a sort package search on this list
  // of entries and return an index indicating position.
  // If the returned index is >= len(entries) then a suitable
  // position could not be found.  The index does not guarantee
  // equality, just indicates where the key would be inserted.