{"ast_node_type":"variable","tokens":[{"end":45,"kind":"keyword","start":0,"text":"let"}]}
        let fn_sig = self.tcx.fn_sig(method);
    fn xform_method_sig(&self, method: DefId, args: GenericArgsRef<'tcx>) -> ty::FnSig<'tcx> {
        debug!(?fn_sig);