{"ast_node_type":"variable","tokens":[{"end":42,"kind":"keyword","start":0,"text":"let"}]}
            let sig = drop_fn.fn_sig(tcx);
            let drop_fn = Ty::new_fn_def(tcx, drop_fn_def_id, trait_args);
            let sig = tcx.instantiate_bound_regions_with_erased(sig);