code: func (o TaintOptions) validateFlags() error {
  	// Cannot have a non-empty selector and all flag set. They are mutually exclusive.
  	if o.all && o.selector != "" {
  		return fmt.Errorf("setting 'all' parameter with a non empty selector is prohibited.")
  	}
  	// If both selector and all are not set.
  	if !o.all && o.selector == "" {
  		if len(o.resources) < 2 {
  			return fmt.Errorf("at least one resource name must be specified since 'all' parameter is not set")
  		} else {
  			return nil
  		}
  	}
  	return nil
  }
docs: // validateFlags checks for the validation of flags for kubectl taints.