{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"external_constraints.region_constraints.retain(|outlives|"}]}
        external_constraints.region_constraints.retain(|outlives| {
        let mut unique = HashSet::default();
            outlives.0.as_region().is_none_or(|re| re != outlives.1) && unique.insert(*outlives)