Ability to deselect an option in the Single Select Widget

When using the single select widget as a menu, it would be convenient if users could deselect an option by selecting an option that is already selected, basically like a check box. Currently, once a value is selected, users are unable to undo that selection.

I know that it is possible to put an invisible button over the single select widget and the button can control this type of logic, however the amount of buttons a developer would need to implement is very overwhelming.