code: func (b *Bundle) AddTranslation(lang *language.Language, translations ...translation.Translation) {
  	b.Lock()
  	defer b.Unlock()
  	if b.translations[lang.Tag] == nil {
  		b.translations[lang.Tag] = make(map[string]translation.Translation, len(translations))
  	}
  	currentTranslations := b.translations[lang.Tag]
  	for _, newTranslation := range translations {
  		if currentTranslation := currentTranslations[newTranslation.ID()]; currentTranslation != nil {
  			currentTranslations[newTranslation.ID()] = currentTranslation.Merge(newTranslation)
  		} else {
  			currentTranslations[newTranslation.ID()] = newTranslation
  		}
  	}
  
  	// lang can provide translations for less specific language tags.
  	for _, tag := range lang.MatchingTags() {
  		b.fallbackTranslations[tag] = currentTranslations
  	}
  }
docs: // AddTranslation adds translations for a language.
  //
  // It is useful if your translations are in a format not supported by LoadTranslationFile.