{"ast_node_type":"variable","tokens":[{"end":85,"kind":"keyword","start":0,"text":"let"}]}
        let region = self.next_region_var(RegionVariableOrigin::PatternRegion(span));
    fn new_ref_ty(&self, span: Span, mutbl: Mutability, ty: Ty<'tcx>) -> Ty<'tcx> {
        Ty::new_ref(self.tcx, region, ty, mutbl)