code: func (r *Resource) Id(options ...interface{}) *Resource {
  	if len(options) > 0 {
  		id := ""
  		switch v := options[0].(type) {
  		default:
  			id = v.(string)
  		case int:
  			id = strconv.Itoa(v)
  		case int64:
  			id = strconv.FormatInt(v, 10)
  		}
  		url := r.Url + "/" + id
  		header := r.Headers
  		if header == nil {
  			header = http.Header{}
  		}
  		newR := &Resource{id: id, Url: url, Api: r.Api, Headers: header, Response: &r.Response}
  
  		if len(options) > 1 {
  			newR.Response = options[1]
  		}
  		return newR
  	}
  	return r
  }
docs: // Same as Res() Method, but returns a Resource with url resource/:id