static ViewModelLocator()
        {
            ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default);

            var nav = new NavigationService();

            //nav.Configure(SecondPageKey, typeof(SecondPage));
            SimpleIoc.Default.Register <INavigationService>(() => nav);

            var pons = new PonsRestService();

            pons.SetSecretKey(Constants.PonsApiSecret);
            SimpleIoc.Default.Register <IPonsRestService>(() => pons);
            SimpleIoc.Default.Register <IPonsDictionaryService, PonsDictionaryService>();

            //if (ViewModelBase.IsInDesignModeStatic)
            //{
            //    SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();
            //}
            //else
            //{
            //    SimpleIoc.Default.Register<IDataService, DataService>();
            //}

            SimpleIoc.Default.Register <MainViewModel>();
        }
        static ViewModelLocator()
        {
            ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default);

            var pons = new PonsRestService();

            pons.SetSecretKey(Constants.PonsApiSecret);
            SimpleIoc.Default.Register <IPonsRestService>(() => pons);
            SimpleIoc.Default.Register <IPonsDictionaryService, PonsDictionaryService>();
            SimpleIoc.Default.Register <ILanguagesTreeService, LanguagesTreeService>();

            //if (ViewModelBase.IsInDesignModeStatic)
            //{
            //    SimpleIoc.Default.Register<IDataService, Design.DesignDataService>();
            //}
            //else
            //{
            //    SimpleIoc.Default.Register<IDataService, DataService>();
            //}

            SimpleIoc.Default.Register <MainViewModel>();
        }