{"ast_node_type":"other","tokens":[{"end":64,"kind":"keyword","start":0,"text":"Some(ctx.expr_str(fmt.span,"}]}
                        Some(ctx.expr_str(fmt.span, sym::empty))
                    if i == 0 || matches!(fmt.template[i - 1], FormatArgsPiece::Placeholder(_)) {
                    } else {