code: func (s bulkFetchDataSorter) Less(i, j int) bool {
  	if s[i].blockFileNum < s[j].blockFileNum {
  		return true
  	}
  	if s[i].blockFileNum > s[j].blockFileNum {
  		return false
  	}
  
  	return s[i].fileOffset < s[j].fileOffset
  }
docs: // Less returns whether the item with index i should sort before the item with
  // index j.  It is part of the sort.Interface implementation.