{"ast_node_type":"function","tokens":[{"end":89,"kind":"keyword","start":0,"text":"pub(crate)"}]}
    pub(crate) fn known_outlives(&self) -> impl Iterator<Item = (RegionVid, RegionVid)> {
    /// Returns the _non-transitive_ set of known `outlives` constraints between free regions.
        self.outlives.base_edges()