{"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"e1.iter().map(|e|"}]}
            e1.iter().map(|e| (sym::start, e)).chain(e2.iter().map(|e| (sym::end, e))).map(
        let fields = self.arena.alloc_from_iter(
                |(s, e)| {