code: func getOverlappingControllers(c client.ReplicationControllerInterface, rc *api.ReplicationController) ([]api.ReplicationController, error) {
  	rcs, err := c.List(api.ListOptions{})
  	if err != nil {
  		return nil, fmt.Errorf("error getting replication controllers: %v", err)
  	}
  	var matchingRCs []api.ReplicationController
  	rcLabels := labels.Set(rc.Spec.Selector)
  	for _, controller := range rcs.Items {
  		newRCLabels := labels.Set(controller.Spec.Selector)
  		if labels.SelectorFromSet(newRCLabels).Matches(rcLabels) || labels.SelectorFromSet(rcLabels).Matches(newRCLabels) {
  			matchingRCs = append(matchingRCs, controller)
  		}
  	}
  	return matchingRCs, nil
  }
docs: // getOverlappingControllers finds rcs that this controller overlaps, as well as rcs overlapping this controller.