Sets a single option in the Combo by its index, returning True if it was able too.

def _set_option_by_index(self, index):
        """
        Sets a single option in the Combo by its index, returning True if it was able too.
        """
        if index < len(self._options):
            self._selected.set(self._options[index])
            return True
        else:
            return False