code: func (model *Model) Save(filename string) error {
  	f, err := os.Create(filename)
  	if err != nil {
  		log.Println("Fuzzy model:", err)
  		return err
  	}
  	defer f.Close()
  	_, err = model.WriteTo(f)
  	if err != nil {
  		log.Println("Fuzzy model:", err)
  		return err
  	}
  	return nil
  }
docs: // Save a spelling model to disk