code: func (u *ID) AppendValues(values Values) {
  	values.Set("level", fmt.Sprintf("%d", u.Epoch.Level))
  	values.Set("time", fmt.Sprintf("%d", u.Epoch.Time))
  	u.Feed.AppendValues(values)
  }
docs: // AppendValues serializes this structure into the provided string key-value store
  // useful to build query strings