@Test
    void testProjectBuilder() throws Exception {
        File f = getFileForClasspathResource("canonical-pom.xml");

        MavenProject project = getProject(f);

        // ----------------------------------------------------------------------
        // Top-level elements
        // ----------------------------------------------------------------------

        List<MavenProject> projects = new ArrayList<>(results.size());

        long totalProblemsCount = 0;

        for (ProjectBuildingResult result : results) {
            projects.add(result.getProject());

            int problemsCount = result.getProblems().size();
            totalProblemsCount += problemsCount;
            if (problemsCount != 0 && LOGGER.isWarnEnabled()) {
                LOGGER.warn("");

     *
     * @return The project that was built or {@code null} if an error occurred and this result accompanies a
     *         {@link ProjectBuildingException}.
     */
    MavenProject getProject();

    /**
     * Gets the problems that were encountered during the project building.
     *
     * @return The problems that were encountered during the project building, can be empty but never {@code null}.
     */

        return DEFAULT_MESSAGE + " (project: " + project.getId() + "; illegal attachment: " + artifact.getId() + ")";
    }

    public MavenProject getProject() {
        return project;
    }

    public Artifact getArtifact() {
        return artifact;
    }

    public ProjectBuildingResult build(File pomFile, ProjectBuildingRequest configuration)
            throws ProjectBuildingException {
        ProjectBuildingResult result = super.build(pomFile, configuration);

        result.getProject().setRemoteArtifactRepositories(Collections.emptyList());

        return result;
    }

    @Override
    public String getProjectId() {
        return projectId;
    }

    @Override
    public File getPomFile() {
        return pomFile;
    }

    @Override
    public MavenProject getProject() {
        return project;
    }

    @Override
    public List<ModelProblem> getProblems() {
        return problems;
    }

    @Override

        final ProjectDependencyGraphStub dependencyGraphStub = new ProjectDependencyGraphStub();
        session.setProjectDependencyGraph(dependencyGraphStub);
        session.setProjects(dependencyGraphStub.getSortedProjects());
        return session;
    }

        for (Iterator<ProjectSegment> it = projectBuilds.iterator(); it.hasNext(); ) {
            ProjectSegment projectBuild = it.next();

            logger.debug("Project: " + projectBuild.getProject().getId());
            logger.debug("Tasks:   " + projectBuild.getTaskSegment().getTasks());
            logger.debug("Style:   " + (projectBuild.getTaskSegment().isAggregating() ? "Aggregating" : "Regular"));

    List<Project> getProjects(List<org.apache.maven.project.MavenProject> projects);

    /**
     * May return null if the input project is null or is not part of the reactor.
     */
    @Nullable
    Project getProject(org.apache.maven.project.MavenProject project);

    List<org.apache.maven.artifact.repository.ArtifactRepository> toArtifactRepositories(
            List<RemoteRepository> repositories);

     */
    private final ConcurrentMap<String, ConcurrentMap<String, ConcurrentMap<String, Object>>>
            pluginContextsByProjectAndPluginKey = new ConcurrentHashMap<>();

    public void setProjects(List<MavenProject> projects) {
        if (!projects.isEmpty()) {
            MavenProject first = projects.get(0);
            this.currentProject = ThreadLocal.withInitial(() -> first);