def custom_str(self, sc_expr_str_fn):
        """
        Works like Symbol.__str__(), but allows a custom format to be used for
        all symbol/choice references. See expr_str().
        """
        return "\n\n".join(node.custom_str(sc_expr_str_fn)
                           for node in self.nodes)

        Works like Symbol.__str__(), but allows a custom format to be used for
        all symbol/choice references. See expr_str().
        
buildroot-external/scripts/kconfiglib.py