{"ast_node_type":"other","tokens":[{"end":63,"kind":"keyword","start":0,"text":"fold_regions(self.infcx.tcx,"}]}
        fold_regions(self.infcx.tcx, value, |_region, _depth| {
        let origin = NllRegionVariableOrigin::Existential { from_forall: false };
            self.infcx.next_nll_region_var(origin, || region_ctxt_fn())