to.parents.remove(from);
    }

    List<String> visitAll() {
        return visitAll(vertices.values(), new HashMap<>(), new ArrayList<>());
    }

    List<String> findCycle(Vertex vertex) {
        return visitCycle(Collections.singleton(vertex), new HashMap<>(), new LinkedList<>());
    }

    private static List<String> visitAll(

    }

    @Override
    public List<String> computePhases(Lifecycle lifecycle) {
        Graph graph = new Graph();
        addPhases(graph, null, null, lifecycle.v3phases());
        List<String> allPhases = graph.visitAll();
        Collections.reverse(allPhases);
        List<String> computed =
                allPhases.stream().filter(s -> !s.startsWith("$")).collect(Collectors.toList());
        return computed;
    }

pkg flag, func Uint64Var(*uint64, string, uint64, string)
pkg flag, func UintVar(*uint, string, uint, string)
pkg flag, func Var(Value, string, string)
pkg flag, func Visit(func(*Flag))
pkg flag, func VisitAll(func(*Flag))
pkg flag, method (*FlagSet) Arg(int) string
pkg flag, method (*FlagSet) Args() []string
pkg flag, method (*FlagSet) Bool(string, bool, string) *bool