{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
    fn relate_universal_regions(&mut self, fr_a: RegionVid, fr_b: RegionVid) {
    /// `inverse_outlives_relation`) that `fr_a: fr_b`.
        debug!("relate_universal_regions: fr_a={:?} outlives fr_b={:?}", fr_a, fr_b);