code: func ParseNetlist(s string) (*Netlist, error) {
  	ws := strings.NewReplacer(" ", "", "\n", "", "\t", "")
  	masks := strings.Split(ws.Replace(s), ",")
  	l := make(Netlist, 0)
  	for _, mask := range masks {
  		if mask == "" {
  			continue
  		}
  		_, n, err := net.ParseCIDR(mask)
  		if err != nil {
  			return nil, err
  		}
  		l = append(l, *n)
  	}
  	return &l, nil
  }
docs: // ParseNetlist parses a comma-separated list of CIDR masks.
  // Whitespace and extra commas are ignored.