code: func (p *Paths) GetLangSubDir(lang string) string {
  	if !p.multilingual {
  		return ""
  	}
  
  	if p.Languages.IsMultihost() {
  		return ""
  	}
  
  	if lang == "" || (lang == p.DefaultContentLanguage && !p.defaultContentLanguageInSubdir) {
  		return ""
  	}
  
  	return lang
  }
docs: // GetLangSubDir returns the given language's subdir if needed.