code: func FormatLabelSelector(labelSelector *LabelSelector) string {
  	selector, err := LabelSelectorAsSelector(labelSelector)
  	if err != nil {
  		return "<error>"
  	}
  
  	l := selector.String()
  	if len(l) == 0 {
  		l = "<none>"
  	}
  	return l
  }
docs: // FormatLabelSelector convert labelSelector into plain string