code: func dropEmpty(list []*string) []string {
  	var l []string
  	for _, s := range list {
  		if *s != "" {
  			l = append(l, *s)
  		}
  	}
  	return l
  }
docs: // dropEmpty list takes a slice of string pointers, and outputs a slice of
  // non-empty strings associated with the flag.