{"ast_node_type":"other","tokens":[{"end":35,"kind":"keyword","start":0,"text":")"}]}
    ) -> Option<ConditionSet<'a>> {
        f: impl Fn(Condition) -> Option<Condition>,
        let set = arena.try_alloc_from_iter(self.iter().map(|c| f(c).ok_or(()))).ok()?;