Map<MavenProject, List<MavenProject>> projects = new HashMap<>();
        projects.put(p1, Collections.emptyList());
        projects.put(p2, Collections.singletonList(p1));

        BuildPlan plan = calculateLifecycleMappings(projects, "verify");
        plan.then(calculateLifecycleMappings(projects, "install"));

        Stream.of(p1, p2).forEach(project -> {

        projects.add(project1);
        MavenProject project2 = createProject("groupId", "artifactId2", "1.0");
        projects.add(project2);
        project1.getDependencies().add(createDependency(project2));

        projects = new ProjectSorter(projects).getSortedProjects();

        assertEquals(project2, projects.get(0));
        assertEquals(project1, projects.get(1));
    }

    @Test

import org.apache.maven.project.CycleDetectedException;
import org.apache.maven.project.DuplicateProjectException;
import org.apache.maven.project.MavenProject;
import org.apache.maven.project.ProjectBuildingException;
import org.apache.maven.project.collector.MultiModuleCollectionStrategy;
import org.apache.maven.project.collector.PomlessCollectionStrategy;
import org.apache.maven.project.collector.RequestPomCollectionStrategy;

        initRepoSession(request, configuration);

        List<MavenProject> projects = new ArrayList<>();

        if (pom != null) {
            MavenProject project = projectBuilder.build(pom, configuration).getProject();

            projects.add(project);
            if (includeModules) {
                for (String module : project.getModules()) {
                    File modulePom = new File(pom.getParentFile(), module);

    }

    @Override
    public List<Project> getProjects(List<MavenProject> projects) {
        return projects == null ? null : map(projects, this::getProject);
    }

    @Override
    public Project getProject(MavenProject project) {
        return project != null && project.getBasedir() != null
                ? allProjects.computeIfAbsent(project.getId(), id -> new DefaultProject(this, project))
                : null;
    }

 */
public class GradleDslReferencePlugin implements Plugin<Project> {
    @Override
    public void apply(Project project) {
        ProjectLayout layout = project.getLayout();
        TaskContainer tasks = project.getTasks();
        ObjectFactory objects = project.getObjects();

        GradleDocumentationExtension extension = project.getExtensions().getByType(GradleDocumentationExtension.class);

            if (projects != null) {
                Map<String, Map<String, Map<String, MavenProject>>> map = new HashMap<>();
                projects.forEach(project -> map.computeIfAbsent(project.getGroupId(), k -> new HashMap<>())
                        .computeIfAbsent(project.getArtifactId(), k -> new HashMap<>())
                        .put(project.getVersion(), project));
                this.projects = map;
            } else {

        File f = getFileForClasspathResource(DIR + "project-with-scoped-dependencies.xml");

        MavenProject project = getProjectWithDependencies(f);

        Artifact artifact;

        assertNotNull(project, "Test project can't be null!");

        checkArtifactIdScope(project, "provided", "provided");
        checkArtifactIdScope(project, "test", "test");
        checkArtifactIdScope(project, "compile", "compile");

        this.mojoExecution = mojoExecution;
    }

    public PluginExecutionException(
            MojoExecution mojoExecution, MavenProject project, String message, Throwable cause) {
        super(mojoExecution.getMojoDescriptor(), project, message, cause);
        this.mojoExecution = mojoExecution;
    }

    public PluginExecutionException(MojoExecution mojoExecution, MavenProject project, Exception cause) {

    @Nonnull
    public Map<String, String> getProperties(@Nonnull Project project) {
        return Collections.unmodifiableMap(
                new PropertiesAsMap(getMavenProject(project).getProperties()));
    }

    @Override
    @Nonnull
    public Optional<Project> getExecutionProject(@Nonnull Project project) {
        // Session keep tracks of the Project per project id,