code: func (svc *Service) SetUser(username string) error {
  	u, err := user.Lookup(username)
  	if err != nil {
  		return err
  	}
  	uid, err := strconv.Atoi(u.Uid)
  	if err != nil {
  		return err
  	}
  	gid, err := strconv.Atoi(u.Gid)
  	if err != nil {
  		return err
  	}
  	svc.uid = uint32(uid)
  	svc.gid = uint32(gid)
  	return nil
  }
docs: // SetUser sets the user for a service.