{"ast_node_type":"function","tokens":[{"end":66,"kind":"keyword","start":0,"text":"fn"}]}
            fn visit_ty(&mut self, ty: Ty<'tcx>) -> Self::Result {
            type Result = ControlFlow<ty::GenericArg<'tcx>>;
                if let ty::Infer(ty::TyVar(vid)) = *ty.kind()