code: func NewTranslator(dirname string, fields ...string) (lt *Translator, err error) {
  	lt = &Translator{
  		dirname: dirname,
  		fields:  make(map[string]*FieldTranslator),
  	}
  	for _, field := range fields {
  		lft, err := NewFieldTranslator(dirname, field)
  		if err != nil {
  			return nil, errors.Wrap(err, "making FieldTranslator")
  		}
  		lt.fields[field] = lft
  	}
  	return lt, err
  }
docs: // NewTranslator gets a new Translator.