{"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"args_iter.next().expect(\"already"}]}
                    args_iter.next().expect("already peeked");
                let element = if let TtElement::Leaf(tt::Leaf::Literal(lit)) = next {
                    ConcatMetaVarExprElem::Literal(lit.clone())