impl optimization::Interprocedural for Inlining {
    fn optimize<'src, 'ast>(program: &FirmProgram<'src, 'ast>) -> Outcome {
        let g = CallGraph::new(program).construct();
        let mut g = condensation(g, false);
        g.reverse();
        g.retain_edges(|g, e| {
            let (n1, n2) = g.edge_endpoints(e).unwrap();
            n1 != n2
        });

        let topo_sort = toposort(&g, None).unwrap();
        let mut map = HashMap::new();
        for (idx, node_id) in topo_sort.iter().enumerate() {
            map.insert(RefEq(g.node_weight(*node_id).unwrap()), idx);
        }

        breakpoint!("inline graph", g, &|n: &Vec<FirmMethodP<'src, 'ast>>| {
            Label::from_text(format!(
                "{:?} {}",
                n.iter()
                    .map(|n| n.borrow().def.name.as_str().to_owned())
                    .collect::<Vec<_>>(),
                map.get(&RefEq(n)).unwrap()
            ))
        });

        for node in topo_sort {
            if g.node_weight(node).unwrap().len() != 1 {
                continue;
            }

            for edge in g.edges_directed(node, petgraph::Direction::Outgoing) {
                Inline::inline(*edge.weight());
            }
        }

        Outcome::Unchanged
    }
}