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

     */
    private List<MavenProject> allProjects;

    private MavenProject topLevelProject;

    private ProjectDependencyGraph projectDependencyGraph;

    private boolean parallel;

    /**
     * Plugin context keyed by project ({@link MavenProject#getId()}) and by plugin lookup key

    }

    @Test
    void testMatchingArtifactIdsDifferentGroupIds() throws Exception {
        List<MavenProject> projects = new ArrayList<>();
        MavenProject project1 = createProject("groupId1", "artifactId", "1.0");
        projects.add(project1);
        MavenProject project2 = createProject("groupId2", "artifactId", "1.0");
        projects.add(project2);

        MavenProject mavenProject = new MavenProject();
        mavenProject.setArtifact(new DefaultArtifact("g", "a", "1.0", Artifact.SCOPE_TEST, "jar", "", null));
        File artifactFile = Files.createTempFile("foo", "tmp").toFile();
        try {
            mavenProjectHelper.attachArtifact(mavenProject, "java-source", artifactFile);
            assertEquals(1, mavenProject.getAttachedArtifacts().size());

import org.apache.maven.project.MavenProject;
import org.apache.maven.project.ProjectSorter;

/**
 * Describes the interdependencies between projects in the reactor.
 *
 */
public class DefaultProjectDependencyGraph implements ProjectDependencyGraph {

    private final ProjectSorter sorter;

    private final List<MavenProject> allProjects;

    private final Map<MavenProject, Integer> order;

    private Map<String, Map<String, Map<String, MavenProject>>> getAllProjects() {
        // compute the projects mapping
        if (allProjects == null) {
            List<MavenProject> allProjects = session.getAllProjects();
            if (allProjects != null) {
                Map<String, Map<String, Map<String, MavenProject>>> map = new HashMap<>();

        return project;
    }

    private MavenProject getMavenProject(String artifactId) {
        MavenProject mavenProject = new MavenProject();
        mavenProject.setGroupId(GROUP_ID);
        mavenProject.setArtifactId(artifactId);
        mavenProject.setVersion("1.0");
        mavenProject.setPomFile(new File(artifactId, "pom.xml"));
        mavenProject.setCollectedProjects(new ArrayList<>());

import java.util.concurrent.CopyOnWriteArrayList;

import org.apache.maven.project.DependencyResolutionResult;
import org.apache.maven.project.MavenProject;

public class DefaultMavenExecutionResult implements MavenExecutionResult {
    private MavenProject project;

    private List<MavenProject> topologicallySortedProjects = Collections.emptyList();

    private DependencyResolutionResult dependencyResolutionResult;

    public LifecycleExecutionException(String message, MavenProject project) {
        super(message);
        this.project = project;
    }

    public LifecycleExecutionException(String message, MojoExecution execution, MavenProject project) {
        super(message);
        this.project = project;
    }

    public LifecycleExecutionException(String message, MojoExecution execution, MavenProject project, Throwable cause) {

    }

    private MavenProject createMavenProject(String artifactId) {
        MavenProject project = new MavenProject();
        project.setGroupId("test");
        project.setArtifactId(artifactId);
        return project;
    }

    private Dependency toDependency(MavenProject mavenProject) {
        Dependency dependency = new Dependency();