assertNotNull(versionFilter);
        assertTrue(versionFilter instanceof ContextualSnapshotVersionFilter);

        request.getUserProperties().put("maven.versionFilters", "h");
        versionFilter = systemSessionFactory.newRepositorySession(request).getVersionFilter();
        assertNotNull(versionFilter);
        assertTrue(versionFilter instanceof HighestVersionFilter);

            if (metadata instanceof ProjectArtifactMetadata) {
                org.eclipse.aether.artifact.Artifact pomArtifact = new SubArtifact(mainArtifact, "", "pom");
                pomArtifact = pomArtifact.setFile(((ProjectArtifactMetadata) metadata).getFile());
                request.addArtifact(pomArtifact);
            } else if (metadata instanceof SnapshotArtifactRepositoryMetadata

                    if (res.getRepository() instanceof org.eclipse.aether.repository.LocalRepository) {
                        return Optional.of(new DefaultLocalRepository(
                                (org.eclipse.aether.repository.LocalRepository) res.getRepository()));
                    } else if (res.getRepository() instanceof org.eclipse.aether.repository.RemoteRepository) {

                pomArtifact = resolveResult.getArtifact();
                result.setRepository(resolveResult.getRepository());
            } catch (ArtifactResolutionException e) {
                if (e.getCause() instanceof ArtifactNotFoundException) {
                    missingDescriptor(session, trace, a, (Exception) e.getCause());
                    if ((getPolicy(session, a, request) & ArtifactDescriptorPolicy.IGNORE_MISSING) != 0) {

        if (this == other) {
            return true;
        }

        if (!(other instanceof ArtifactVersion)) {
            return false;
        }

        return compareTo((ArtifactVersion) other) == 0;
    }

    public int compareTo(ArtifactVersion otherVersion) {
        if (otherVersion instanceof DefaultArtifactVersion) {

    }

    @Override
    public org.eclipse.aether.repository.RemoteRepository toRepository(RemoteRepository repository) {
        if (repository instanceof DefaultRemoteRepository) {
            return ((DefaultRemoteRepository) repository).getRepository();
        } else {
            // TODO
            throw new UnsupportedOperationException("Not implemented yet");

            boolean normalized = false;

            List<ArtifactRepository> repos = new ArrayList<>(repositories.size());

            for (Object repository : repositories) {
                if (repository instanceof Repository) {
                    try {
                        ArtifactRepository repo = repositorySystem.buildArtifactRepository((Repository) repository);

        this.typeRegistry = requireNonNull(typeRegistry, "typeRegistry");
    }

    @Override
    public ArtifactType get(String typeId) {
        Type type = typeRegistry.require(typeId);
        if (type instanceof ArtifactType) {
            return (ArtifactType) type;
        }
        if (type != null) {
            return new DefaultType(
                    type.id(),
                    type.getLanguage(),

        this.sessionFactory = sessionFactory;
    }

    @Override
    public void init(Context context) throws Exception {}

    @Override
    public void onEvent(Object arg) throws Exception {
        if (arg instanceof ExecutionEvent) {
            ExecutionEvent ee = (ExecutionEvent) arg;
            InternalMavenSession session =
                    InternalMavenSession.from(ee.getSession().getSession());

        this.artifactHandlers = requireNonNull(artifactHandlers);
    }

    @Override
    public void onEvent(Object event) {
        if (event instanceof ExecutionEvent) {
            ExecutionEvent executionEvent = (ExecutionEvent) event;
            if (executionEvent.getType() == ExecutionEvent.Type.SessionEnded) {
                allHandlers.clear();
            }