async void OnItemSelected(object sender, SelectedItemChangedEventArgs args)
        {
            var warranty = args.SelectedItem as Warranty;

            if (warranty == null)
            {
                return;
            }

            var itemVM = new WarrantyDetailViewModel(warranty);
            await itemVM.InitAsync();

            await Navigation.PushAsync(new ItemDetailPage(itemVM));

            // Manually deselect item
            ItemsListView.SelectedItem = null;
        }
        public ItemDetailPage(WarrantyDetailViewModel viewModel)
        {
            InitializeComponent();

            BindingContext = this.viewModel = viewModel;
        }