code: func (svc *Service) SetPriority(priority int) error {
  	if priority < -20 || priority > 19 {
  		return fmt.Errorf("Invalid priority %d - must be between -20 and 19", priority)
  	}
  	svc.priority = priority
  	return nil
  }
docs: // SetPriority sets the process priority for a service.