code: func (w *Watchdog) AddService(name, binary string) (*Service, error) {
  	if _, ok := w.services[name]; ok {
  		return nil, fmt.Errorf("Service %q already exists", name)
  	}
  
  	svc := newService(name, binary)
  	w.services[name] = svc
  
  	return svc, nil
  }
docs: // AddService adds a service that is to be run by the watchdog.