{"ast_node_type":"function","tokens":[{"end":84,"kind":"keyword","start":0,"text":"pub(super)"}]}
    pub(super) fn to_error_region(&self, r: RegionVid) -> Option<ty::Region<'tcx>> {
    /// one (e.g., this is just some random part of the CFG).
        self.to_error_region_vid(r).and_then(|r| self.regioncx.region_definition(r).external_name)