{"ast_node_type":"variable","tokens":[{"end":44,"kind":"keyword","start":0,"text":"let"}]}
            let output = fn_ptr_ty.output();
                tcx.collect_constrained_late_bound_regions(inputs.map_bound(|i| i.to_owned()));
            let late_bound_in_ret = tcx.collect_referenced_late_bound_regions(output);