RxUI combobox hack binding

HackBinding.txt

XAML
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<ComboBox Grid.Row="0" x:Name="gardens" Margin="10" FontSize="24">
    <ComboBoxItem>New...</ComboBoxItem>
    <ComboBoxItem>G1</ComboBoxItem>
    <ComboBoxItem>G2</ComboBoxItem>
    <ComboBoxItem>G3</ComboBoxItem>
</ComboBox>


Code Behind
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this.WhenAny(x => x.gardens.SelectedItem, x => x.Value)
                .Select(x => x == null ? string.Empty : x.ToString())
                .BindTo(this, x => x.ViewModel.SelectedGarden);
                
                
ViewModel code
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private string _SelectedGarden;
public string SelectedGarden
{
    get { return _SelectedGarden; }
    set { this.RaiseAndSetIfChanged(ref _SelectedGarden, value); }
}