protected override IArticle[] GetArticleList(string groupName, int startNumber, int endNumber)
 {
     try
     {
         var articleList = webService.ArticleList(groupName, startNumber, endNumber);
         // sometimes web-service return null....
         if (articleList != null)
         {
             var iArticles = new IArticle[articleList.articles.Length];
             for (var i = 0; i < iArticles.Length; i++)
             {
                 iArticles[i] = new Article(articleList.articles[i]);
             }
             return(iArticles);
         }
         return(new Article[0]);
     }
     catch (Exception exception)
     {
         ProcessException(exception);
         return(null);
     }
 }