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(

        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(

        addEdge(graph1, "b", "c");
        List<String> expected1 = new ArrayList<>();
        expected1.add("c");
        expected1.add("b");
        expected1.add("a");
        List<String> actual1 = graph1.visitAll();
        assertEquals(expected1, actual1);

        Graph graph2 = new Graph();
        graph2.addVertex("a");
        graph2.addVertex("b");
        graph2.addVertex("c");
        addEdge(graph2, "b", "a");

                            false,
                            true);
                }
            }
        }

        List<String> sortedProjectLabels = graph.visitAll();

        this.sortedProjects = sortedProjectLabels.stream()
                .map(id -> projectMap.get(id))
                .collect(Collectors.collectingAndThen(Collectors.toList(), Collections::unmodifiableList));

    }

    @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;
    }