{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"//"}]}
        // is subtle: these arenas are reentrant. In other words, `iter` may very well be holding a
        // Despite the similarlty with `DroplessArena`, we cannot reuse their fast case. The reason
        // reference to `self` and adding elements to the arena during iteration.