code: func subresourceListString(data []interface{}) string {
  	var strs []string
  	for _, v := range data {
  		if v == nil {
  			strs = append(strs, "(<nil>)")
  			continue
  		}
  		m := v.(map[string]interface{})
  		devaddr := m["device_address"].(string)
  		if devaddr == "" {
  			devaddr = "<new device>"
  		}
  		strs = append(strs, fmt.Sprintf("(key %d at %s)", m["key"].(int), devaddr))
  	}
  	return strings.Join(strs, ",")
  }
docs: // subresourceListString takes a list of sub-resources and pretty-prints the
  // key and device address.