def unset_value(self):
        """
        Resets the user value (mode) and user selection of the Choice, as if
        the user had never touched the mode or any of the choice symbols.
        """
        if self.user_value is not None or self.user_selection:
            self.user_value = self.user_selection = None
            self._rec_invalidate()
Resets the user value (mode) and user selection of the Choice, as if
        the user had never touched the mode or any of the choice symbols.