{"ast_node_type":"variable","tokens":[{"end":99,"kind":"keyword","start":0,"text":"let"}]}
                let r = ty::Region::new_late_param(self.infcx.tcx, self.mir_def.to_def_id(), kind);
                let kind = ty::LateParamRegionKind::from_bound(ty::BoundVar::from_usize(idx), kind);
                let region_vid = {