code: func parseLabels(flagLabels *kvMap) types.UserLabels {
  	if flagLabels.IsEmpty() {
  		return nil
  	}
  	labels := make(types.UserLabels)
  	for k, v := range flagLabels.mapping {
  		labels[k] = v
  	}
  	return labels
  }
docs: // parseLabels converts the labels set by '--user-label' flag,
  // and returns types.UserLabels.