* @see org.eclipse.aether.RepositoryEvent
     */
    void onEvent(Object event) throws Exception;

    /**
     * Notifies the spy of Maven's termination, allowing it to free any resources allocated by it.
     */
    void close() throws Exception;

    //
    // 10) Create ProjectDependencyGraph without trimming (as trimming was done in 7). A new topological sort is
    // required after the execution of 9) as the AbstractLifecycleParticipants are free to mutate the MavenProject
    // instances, which may change dependencies which can, in turn, affect the build order.
    //
    // 11) Execute LifecycleStarter.start()
    //

        assertEquals("https://project.url/license", pom.getValue("licenses[1]/url"));
        assertEquals("repo", pom.getValue("licenses[1]/distribution"));
        assertEquals("free", pom.getValue("licenses[1]/comments"));

        assertEquals(1, ((List<?>) pom.getValue("developers")).size());
        assertEquals("dev", pom.getValue("developers[1]/id"));

     *
     * @param request the dependency collection request, must not be {@code null}
     * @return the collection result, never {@code null}
     * @throws DependencyCollectorException if the dependency tree could not be built
     * @throws IllegalArgumentException if an argument is null or invalid
     *
     * @see DependencyCollector#collect(Session, Project)
     * @see DependencyCollector#collect(Session, DependencyCoordinate)

import org.eclipse.aether.resolution.ArtifactRequest;
import org.eclipse.aether.util.artifact.ArtifactIdUtils;

import static java.util.Objects.requireNonNull;

/**
 * A class building reverse tree using {@link CollectStepData} trace data provided in {@link RepositoryEvent}
 * events fired during collection.
 *
 * @since 3.9.0
 */
class ReverseTreeRepositoryListener extends AbstractRepositoryListener {
    @Override

     *
     * @param projectBuildingRequest The project building request, may be {@code null}.
     * @since 2.1
     */
    // used by maven-dependency-tree
    @Deprecated
    public void setProjectBuildingRequest(ProjectBuildingRequest projectBuildingRequest) {
        this.projectBuilderConfiguration = projectBuildingRequest;
    }

    /**

 *
 */
public interface ModelInterpolator {

    /**
     * Interpolates expressions in the specified model. Note that implementations are free to either interpolate the
     * provided model directly or to create a clone of the model and interpolate the clone. Callers should always use
     * the returned model and must not rely on the input model being updated.
     *

    // -----------------------------------------------------------------------------------------------

    // TODO These two tests display a lack of symmetry with respect to the input which is a free form string and the
    //      mojo descriptor which comes back. All the free form parsing needs to be done somewhere else, this is
    //      really the function of the CLI, and then the pre-processing of that output still needs to be fed into

    /**
     * construct graph from a "dirty" tree
     */
    public MetadataGraph(MetadataTreeNode tree) throws MetadataResolutionException {
        this(tree, false, false);
    }
    // ------------------------------------------------------------------------
    /**
     * construct graph from a "dirty" tree
     *
     * @param tree "dirty" tree root

            return null;
        }

        MetadataTreeNode tree = null;
        MetadataTreeNode parent = null;

        for (ArtifactMetadata md : classpath) {
            MetadataTreeNode node = new MetadataTreeNode(md, parent, md.isResolved(), md.getArtifactScope());
            if (tree == null) {
                tree = node;
            }

            if (parent != null) {