{"ast_node_type":"other","tokens":[{"end":68,"kind":"keyword","start":0,"text":"//"}]}
        // We must not erase bound regions. `for<'a> fn(&'a ())` and
    fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> {
        // `fn(&'free ())` are different types: they may implement different