code: func (v *Vserver) AddHealthcheck(h *Healthcheck) error {
  	key := h.Key()
  	if _, ok := v.Healthchecks[key]; ok {
  		return fmt.Errorf("Vserver %q already contains Healthcheck %q", v.Name, key)
  	}
  	v.Healthchecks[key] = h
  	return nil
  }
docs: // AddHealthcheck adds a Healthcheck to a Vserver.