public GraphsPageViewModel(IGlobalBusyIndicatorManager busyIndicatorManager, IErrorHandler errorHandler, IGraphsProxyServer graphsProxyServer, INavigationService navigationService, IAnalyticsService analyticsService)
     : base(busyIndicatorManager, errorHandler, navigationService)
 {
     _graphsProxyServer = graphsProxyServer;
     _analyticsService  = analyticsService;
 }