public StoriesViewModel()
        {
            EndPoint = Singleton.EndPoint;

            MenuItems = new List <string>();
            MenuItems.Add("Best");
            MenuItems.Add("Top");
            MenuItems.Add("New");
            MenuItems.Add("Ask");

            this.GetStoriesCommand    = new GetStoriesCommand(this);
            this.ChangeContextCommand = new ChangeContextCommand(this);
            this.GoToUrlCommand       = new GoToUrlCommand(this);

            GetStories("top");

            if (DesignerProperties.GetIsInDesignMode(new DependencyObject()))
            {
                Add(new StoryModel {
                    By = "me", Score = 1000, Title = "Pollo"
                });
                Add(new StoryModel {
                    By = "me", Score = 1000, Title = "Empanadas"
                });
                Add(new StoryModel {
                    By = "me", Score = 1000, Title = "Chipas"
                });
            }
        }
 static Singleton()
 {
     EndPoint = new HackerNewsEndPoint();
 }