private async Task ModalBettingPage(BettingItemModel bettingItem, bool side)
        {
            var item = bettingItem;

            item.Side    = side;
            item.Address = String.Empty;

            SelectedItem = item;

            await Navigation.PushModalAsync(new BettingCreatePage(this));
        }
        private async Task ModalHistoryPage(BettingItemModel bettingItem)
        {
            SelectedItem = bettingItem;

            await Navigation.PushModalAsync(new HistoryPage(viewModelContext : this));
        }