{"ast_node_type":"function","tokens":[{"end":97,"kind":"keyword","start":0,"text":"pub(crate)"}]}
    pub(crate) fn reverse_graph(&self, num_region_vars: usize) -> graph::ReverseConstraintGraph {
    /// represents an edge `R2 -> R1`.
        graph::ConstraintGraph::new(graph::Reverse, self, num_region_vars)