ProjectDependencyGraph projectDependencyGraph = new ProjectDependencyGraphStub();

        ConcurrencyDependencyGraph graph = new ConcurrencyDependencyGraph(projectBuildList, projectDependencyGraph);

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

        List<MavenProject> rootSchedulableBuilds = graph.getRootSchedulableBuilds();