private async void Button_Click_1(object sender, RoutedEventArgs e)
        {
            var foo = new Foo();

            // OK, depends on the usage.
            await foo.BarAsync().ConfigureAwait(false);
        }
        private async void Button_Click(object sender, RoutedEventArgs e)
        {
            var foo = new Foo();

            // OK, no .ConfigureAwait required.
            await foo.BarAsync();
        }