Restaurant.ViewModels.MainViewModel.MainViewModel C# (CSharp) Method

        public MainViewModel(UserInfo user, IDetailedScreen screen = null)
        {
            DetailScreen = (screen ?? Locator.Current.GetService<IDetailedScreen>());
            Locator.CurrentMutable.RegisterConstant(this, typeof(MainViewModel));
            Locator.CurrentMutable.RegisterConstant(new BasketViewModel(), typeof(BasketViewModel));
            Locator.CurrentMutable.RegisterConstant(new FoodsViewModel(), typeof(FoodsViewModel));
            FoodViewModel = Locator.Current.GetService<FoodsViewModel>();
            BasketViewModel = Locator.Current.GetService<BasketViewModel>();
            User = user;
        }