public class DefaultProjectDependencyGraph implements ProjectDependencyGraph {

    private final ProjectSorter sorter;

    private final List<MavenProject> allProjects;

    private final Map<MavenProject, Integer> order;

    private final Map<String, MavenProject> projects;

    /**
     * Creates a new project dependency graph based on the specified projects.
     *

                        "site")),
                pom.getValue("reporting/outputDirectory"));
    }

    @Test
    void testPluginOrder() throws Exception {
        PomTestWrapper pom = buildPom("plugin-order");
        assertEquals("plexus-component-metadata", pom.getValue("build/plugins[1]/artifactId"));
        assertEquals("maven-surefire-plugin", pom.getValue("build/plugins[2]/artifactId"));
    }

    @Test

import org.eclipse.aether.resolution.ArtifactDescriptorResult;

/**
 * Maven relocation source.
 * Note: implementations of this component should avoid the "default" name (has special meaning in Eclipse Sisu) and
 * explicitly order implementations using Sisu priorities.
 *
 * @since 4.0.0
 */
public interface MavenArtifactRelocationSource {
    /**
     * Returns {@link Artifact} instance where to relocate to, or {@code null}.
     *

     *
     * @return the severity level of this problem, never {@code null}
     */
    @Nonnull
    Severity getSeverity();

    /**
     * The different severity levels for a problem, in decreasing order.
     *
     * @since 4.0.0
     */
    @Experimental
    enum Severity {
        FATAL, //
        ERROR, //
        WARNING //
    }

         * NOTE: This is primarily to keep backward-compat with Maven 2.x which did not validate that dependencies are
         * unique within a single POM. Upon multiple declarations, 2.x just kept the last one but retained the order of
         * the first occurrence. So when we're in lenient/compat mode, we have to deal with such broken POMs and mimic

// TODO lifecycles being executed
// TODO what runs in each phase
// TODO plugins that need downloading
// TODO project dependencies that need downloading
// TODO unfortunately the plugins need to be downloaded in order to get the plugin.xml file. need to externalize this
//      from the plugin archive.
// TODO this will be the class that people get in IDEs to modify

/**
 * MavenExecutionPlan
 */

        // because the participant is free to change the dependencies of a project which can potentially change the
        // topological order of the projects, and therefore can potentially change the build order.
        //
        // Note that participants may affect the topological order of the projects but it is
        // not expected that a participant will add or remove projects from the session.
        //

                return rx - lx;
            } else {
                return lx - rx;
            }
        };

        Map<String, Lifecycle> lifecyclesMap = lookupLifecycles();

        // ensure canonical order of standard lifecycles
        return lifecyclesMap.values().stream()
                .peek(l -> Objects.requireNonNull(l.getId(), "A lifecycle must have an id."))

        declaringProject.getModel().setBuild(build);

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

        assertEquals(parentProject, projects.get(0));

        // the order of these two is non-deterministic, based on when they're added to the reactor.
        assertThat(projects, hasItem(pluginProject));
        assertThat(projects, hasItem(pluginLevelDepProject));

    @Override
    String id();

    /**
     * Collection of phases for this lifecycle
     */
    Collection<Phase> phases();

    /**
     * Pre-ordered list of phases.
     * If not provided, a default order will be computed.
     */
    default Optional<List<String>> orderedPhases() {
        return Optional.empty();
    }

    /**
     * A phase in the lifecycle.
     */
    interface Phase {