code: func ListSnapshots(dirpath string) ([]string, error) {
  	dirents, err := ioutil.ReadDir(dirpath)
  	if err != nil {
  		return nil, err
  	}
  
  	var snapshots []string
  	for _, dirent := range dirents {
  		if strings.HasSuffix(dirent.Name(), ".snap") {
  			snapshots = append(snapshots, dirent.Name())
  		}
  	}
  
  	// Sort snapshot filenames in reverse lexical order
  	sort.Sort(sort.Reverse(sort.StringSlice(snapshots)))
  	return snapshots, nil
  }
docs: // ListSnapshots lists all the snapshot files in a particular directory and returns
  // the snapshot files in reverse lexical order (newest first)