? request.getArtifact()
                                    .setVersion(lowerBound.getVersion().toString())
                            : null;
                    org.eclipse.aether.artifact.Artifact upperArtifact = upperBound != null
                            ? request.getArtifact()
                                    .setVersion(upperBound.getVersion().toString())

        for (org.eclipse.aether.graph.Dependency dependency : artifactDescriptorResult.getDependencies()) {
            if ("org.apache.maven".equals(dependency.getArtifact().getGroupId())
                    && "maven-compat".equals(dependency.getArtifact().getArtifactId())
                    && !DependencyScope.TEST.is(dependency.getScope())) {
                pluginValidationManager.reportPluginValidationIssue(

            throw result.getErrorArtifactExceptions().get(0);
        }

        if (result.hasMissingArtifacts()) {
            throw new MultipleArtifactsNotFoundException(
                    request.getArtifact(),
                    toList(result.getArtifacts()),
                    result.getMissingArtifacts(),
                    request.getRemoteRepositories());
        }

        Artifact artifact = new AttachedArtifact(project.getArtifact(), artifactType, handler);

        artifact.setFile(artifactFile);
        artifact.setResolved(true);

        attachArtifact(project, artifact);
    }

    @Override
    public void attachArtifact(MavenProject project, File artifactFile, String artifactClassifier) {
        Artifact projectArtifact = project.getArtifact();

     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        try {
            ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
            ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();

            return version1.compareTo(version2) > 0 ? node1 : node2;
        } catch (OverConstrainedVersionException exception) {

                    if (!remoteFile.exists()) {
                        download.setException(new ArtifactNotFoundException(download.getArtifact(), repository));
                    } else {
                        download.setException(new ArtifactTransferException(download.getArtifact(), repository, e));
                    }
                }
            }
        }
        if (metadataDownloads != null) {

        boolean pcdPresent = artifactDescriptorResult.getDependencies().stream()
                .filter(d -> "org.codehaus.plexus".equals(d.getArtifact().getGroupId()))
                .anyMatch(d -> "plexus-container-default".equals(d.getArtifact().getArtifactId()));

        if (pcdPresent) {
            pluginValidationManager.reportPluginValidationIssue(

     */
    AuthenticationInfo getAuthenticationInfo(String id);

    ProxyInfo getProxy(String protocol);

    void getArtifact(Artifact artifact, ArtifactRepository repository)
            throws TransferFailedException, ResourceDoesNotExistException;

    void getArtifact(Artifact artifact, List<ArtifactRepository> remoteRepositories)
            throws TransferFailedException, ResourceDoesNotExistException;

     */

    @Override
    public ResolutionNode resolveConflict(ResolutionNode node1, ResolutionNode node2) {
        try {
            ArtifactVersion version1 = node1.getArtifact().getSelectedVersion();
            ArtifactVersion version2 = node2.getArtifact().getSelectedVersion();

            return version1.compareTo(version2) <= 0 ? node1 : node2;
        } catch (OverConstrainedVersionException exception) {

    //
    // Retriever
    //
    void getArtifact(Artifact artifact, ArtifactRepository repository, TransferListener transferListener, boolean force)
            throws TransferFailedException, ResourceDoesNotExistException;

    void getArtifact(
            Artifact artifact,
            List<ArtifactRepository> remoteRepositories,