{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"let"}]}
            let sig = tcx.fn_sig(drop_fn_def_id).instantiate(tcx, trait_args);
            let trait_args = tcx.mk_args(&[drop_ty.into()]);
            let sig = tcx.instantiate_bound_regions_with_erased(sig);