ConcurrencyDependencyGraph graph =
                new ConcurrencyDependencyGraph(getProjectBuildList(session), dependencyGraph);

        final List<MavenProject> projectBuilds = graph.getRootSchedulableBuilds();
        assertEquals(1, projectBuilds.size());
        assertEquals(A, projectBuilds.iterator().next());

        final List<MavenProject> subsequent = graph.markAsFinished(A);

        // start
        assertEquals(0, graph.getFinishedProjects().size());
        assertEquals(6, graph.getNumberOfBuilds());

        List<MavenProject> rootSchedulableBuilds = graph.getRootSchedulableBuilds();
        // only Project.A has no dependencies
        assertEquals(1, rootSchedulableBuilds.size());
        assertEquals(
                ProjectDependencyGraphStub.A, rootSchedulableBuilds.iterator().next());

     *
     * @return A list of all the initial builds, ordered by priority (critical path first)
     */
    public List<MavenProject> getRootSchedulableBuilds() {
        Set<MavenProject> result = new LinkedHashSet<>();
        for (ProjectSegment projectBuild : projectBuilds) {
            if (projectDependencyGraph

                .map(Map.Entry::getKey)
                .collect(Collectors.toSet());

        // schedule independent projects (ordered by critical path priority)
        for (MavenProject mavenProject : analyzer.getRootSchedulableBuilds()) {
            ProjectSegment projectSegment = projectBuildList.get(mavenProject);
            logger.debug("Scheduling: {}", projectSegment.getProject());
            Callable<ProjectSegment> cb =