{"ast_node_type":"variable","tokens":[{"end":46,"kind":"keyword","start":0,"text":"let"}]}
                let def = tcx.adt_def(def_id);
            ItemKind::Enum(..) | ItemKind::Struct(..) | ItemKind::Union(..) => {
                let args = ty::GenericArgs::identity_for_item(tcx, def_id);