}

    private List<MavenProject> getChildProjects(MavenProject parent, MavenExecutionRequest request) {
        final List<MavenProject> children = parent.getCollectedProjects();
        if (children != null && request.isRecursive()) {
            return children;
        } else {
            return new ArrayList<>();
        }
    }

    private Optional<MavenProject> findOptionalProjectBySelector(

    }

    public List<MavenProject> getUpstreamProjects(MavenProject project, boolean transitive) {
        return applyFilter(projectDependencyGraph.getUpstreamProjects(project, transitive));
    }

    private List<MavenProject> applyFilter(Collection<? extends MavenProject> projects) {
        List<MavenProject> filtered = new ArrayList<>(projects.size());

        for (MavenProject project : projects) {

    }

    /**
     * Finds the first ProjectSegment matching the supplied project
     * @param mavenProject the requested project
     * @return The projectSegment or null.
     */
    public ProjectSegment findByMavenProject(MavenProject mavenProject) {
        return items.stream()
                .filter(pb -> mavenProject.equals(pb.getProject()))
                .findFirst()
                .orElse(null);
    }

import java.util.List;

import org.apache.maven.project.MavenProject;

/**
 * Describes the interdependencies between projects in the reactor.
 *
 * @since 3.0-alpha
 */
public interface ProjectDependencyGraph {

    /**
     * Gets all collected projects.
     *
     * @return All collected projects.
     *
     * @since 3.5.0
     */
    List<MavenProject> getAllProjects();

    /**

                new ConcurrencyDependencyGraph(getProjectBuildList(session), dependencyGraph);

        final List<MavenProject> projectBuilds = graph.getRootSchedulableBuilds();
        assertEquals(1, projectBuilds.size());
        assertEquals(A, projectBuilds.iterator().next());

        final List<MavenProject> subsequent = graph.markAsFinished(A);
        assertEquals(2, subsequent.size());

        File pom0Basedir = pom0.getParentFile();

        File pom1 = new File(pom0Basedir, "p1/pom.xml");

        // load everything...
        MavenProject project0 = getProject(pom0);
        MavenProject project1 = getProject(pom1);

        assertEquals(pom0Basedir, project1.getParent().getBasedir());
    }

import java.util.List;
import java.util.Properties;
import java.util.Set;

import org.apache.maven.artifact.Artifact;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.project.MavenProject;
import org.junit.jupiter.api.Test;

import static org.codehaus.plexus.testing.PlexusExtension.getBasedir;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.endsWith;

        File pom0Basedir = pom0.getParentFile();

        File pom1 = new File(pom0Basedir, "p1/pom.xml");

        // load everything...
        MavenProject project0 = getProjectWithDependencies(pom0);
        MavenProject project1 = getProjectWithDependencies(pom1);

        assertEquals(pom0Basedir, project1.getParent().getBasedir());
        Set set = project1.getArtifacts();

    @Test
    void testADependencies() {
        final List<MavenProject> mavenProjects = stub.getUpstreamProjects(ProjectDependencyGraphStub.A, false);
        assertEquals(0, mavenProjects.size());
    }

    @Test
    void testBDependencies() {
        final List<MavenProject> bProjects = stub.getUpstreamProjects(ProjectDependencyGraphStub.B, false);
        assertEquals(1, bProjects.size());

 * @since 3.1.2
 */
public class MojoExecutionEvent {
    private final MavenSession session;

    private final MavenProject project;

    private final MojoExecution mojoExecution;

    private final Mojo mojo;

    private final Throwable cause;

    public MojoExecutionEvent(MavenSession session, MavenProject project, MojoExecution mojoExecution, Mojo mojo) {
        this(session, project, mojoExecution, mojo, null);
    }