/// <summary>
    /// Gets a list of the available versions of an item.
    /// </summary>
    /// <param name="itemDefinition">The item.</param>
    /// <param name="context">The context.</param>
    /// <returns></returns>
    public override VersionUriList GetItemVersions(ItemDefinition itemDefinition, CallContext context) {
      LanguageCollection languages = GetLanguages(context);
     
      if(languages == null){
        return null;
      }

      VersionUriList result = new VersionUriList();

      foreach(Language language in languages){
        result.Add(language, Version.First);
      }

      return result;
    }