{"ast_node_type":"variable","tokens":[{"end":75,"kind":"keyword","start":0,"text":"let"}]}
        let invoke_ty = trait_object_ty(tcx, ty::Binder::dummy(trait_ref));
        let trait_ref = ty::TraitRef::new_from_args(tcx, trait_id, instance.args);
        instance.args = tcx.mk_args_trait(invoke_ty, trait_ref.args.into_iter().skip(1));