    @Test
    public void testPriorityQueueOrder() {

        MavenProject a = newProject("a"), b = newProject("b"), c = newProject("c");
        TestProjectDependencyGraph graph = new TestProjectDependencyGraph(a, b, c);
        graph.addDependency(b, a);
        DependencyGraph<MavenProject> dp = DependencyGraph.fromMaven(graph, null);

        Comparator<MavenProject> cmp = ProjectComparator.create0(dp, new HashMap<>(), ProjectComparator::id);

        Queue<MavenProject> queue = new PriorityQueue<>(3, cmp);
        queue.add(a);
        queue.add(b);
        queue.add(c);

        Assertions.assertEquals(a, queue.poll());
        Assertions.assertEquals(c, queue.poll());
        Assertions.assertEquals(b, queue.poll());
    }