code: func (fe *fieldError) Translate(ut ut.Translator) string {
  
  	m, ok := fe.v.transTagFunc[ut]
  	if !ok {
  		return fe.Error()
  	}
  
  	fn, ok := m[fe.tag]
  	if !ok {
  		return fe.Error()
  	}
  
  	return fn(ut, fe)
  }
docs: // Translate returns the FieldError's translated error
  // from the provided 'ut.Translator' and registered 'TranslationFunc'
  //
  // NOTE: is not registered translation can be found it returns the same
  // as calling fe.Error()