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

        MavenProject project = mock(MavenProject.class);
        when(project.getGroupId()).thenReturn("org.apache.maven.plugins.overflow");
        when(project.getArtifactId()).thenReturn("maven-project-info-reports-plugin");
        when(project.getPackaging()).thenReturn("maven-plugin");
        when(project.getName()).thenReturn("Apache Maven Project Info Reports Plugin");

        assertEquals(1, ex1.getResults().size());
        MavenProject project1 = ex1.getResults().get(0).getProject();
        assertNotNull(project1);
        assertEquals("testArtifactMissingVersion", project1.getArtifactId());
        assertEquals(pomFile, project1.getFile());

        // multi projects build entry point
        ProjectBuildingException ex2 = assertThrows(
                ProjectBuildingException.class,

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;

        ProjectBuildingRequest request = newBuildingRequest();
        request.setLocalRepository(getLocalRepository());
        request.setActiveProfileIds(List.of("profile1"));

        MavenProject project = projectBuilder.build(testPom, request).getProject();

        String id = project.getGroupId() + ":" + project.getArtifactId() + ":" + project.getVersion();

        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);

            String projectId = getId(project);

            MavenProject conflictingProject = projectMap.put(projectId, project);

            if (conflictingProject != null) {
                throw new DuplicateProjectException(
                        projectId,
                        conflictingProject.getFile(),
                        project.getFile(),
                        "Project '" + projectId + "' is duplicated in the reactor");

            throws DuplicateProjectException {
        Map<String, MavenProject> index = new LinkedHashMap<>();
        Map<String, List<File>> collisions = new LinkedHashMap<>();

        for (MavenProject project : projects) {
            String projectId = ArtifactUtils.key(project.getGroupId(), project.getArtifactId(), project.getVersion());

            if (isBom) {
                return buildBom(session, project, src);
            } else {
                return buildPom(session, project, src);
            }
        } else {
            return buildNonPom(session, project, src);
        }
    }

    protected Model buildPom(RepositorySystemSession session, MavenProject project, ModelSource src)
            throws ModelBuilderException {

        return true;
    }

    private Set<String> getReactorProjectKeys(Collection<MavenProject> projects) {
        Set<String> projectKeys = new HashSet<>(projects.size() * 2);
        for (MavenProject project : projects) {
            String key = ArtifactUtils.key(project.getGroupId(), project.getArtifactId(), project.getVersion());
            projectKeys.add(key);
        }
        return projectKeys;
    }