{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"self.logs[s.undo_len..].iter().filter_map(|log|"}]}
        self.logs[s.undo_len..].iter().filter_map(|log| match log {
    ) -> impl Iterator<Item = &'_ region_constraints::UndoLog<'tcx>> + Clone {
            UndoLog::RegionConstraintCollector(log) => Some(log),