return null;
    }

    @SuppressWarnings("unchecked")
    private ConcurrentMap<Key, PluginVersionResult> getCache(PluginVersionRequest request) {
        SessionData data = request.getRepositorySession().getData();
        return (ConcurrentMap<Key, PluginVersionResult>)
                data.computeIfAbsent(CACHE_KEY, () -> new ConcurrentHashMap<>(256));
    }

    private static Key getKey(PluginVersionRequest request) {

    static CollectStepData lookupCollectStepData(RequestTrace trace) {
        CollectStepData collectStepTrace = null;
        while (trace != null) {
            if (trace.getData() instanceof CollectStepData) {
                collectStepTrace = (CollectStepData) trace.getData();
                break;
            }
            trace = trace.getParent();
        }
        return collectStepTrace;
    }

    /**

    static InternalSession from(org.eclipse.aether.RepositorySystemSession session) {
        return cast(InternalSession.class, session.getData().get(InternalSession.class), "session");
    }

    static void associate(org.eclipse.aether.RepositorySystemSession rsession, Session session) {
        if (!rsession.getData().set(InternalSession.class, null, from(session))) {

        RepositorySystemSession systemSessionMock = Mockito.mock(RepositorySystemSession.class);
        SessionData sessionDataMock = Mockito.mock(SessionData.class);
        when(systemSessionMock.getData()).thenReturn(sessionDataMock);
        when(sessionDataMock.get(any())).thenReturn(new NoTransformerContext());

        Path beforePomFile =

            }
        }
    }

    private List<?> validationPluginExcludes(RepositorySystemSession session) {
        return (List<?>) session.getData().computeIfAbsent(PLUGIN_EXCLUDES_KEY, () -> parsePluginExcludes(session));
    }

    private List<String> parsePluginExcludes(RepositorySystemSession session) {

            }
            mojos.remove(Thread.currentThread());
        }

        private OwnerReentrantLock getProjectLock(MavenSession session) {
            SessionData data = session.getSession().getData();
            Map<MavenProject, OwnerReentrantLock> locks = data.computeIfAbsent(PROJECT_LOCKS, ConcurrentHashMap::new);
            return locks.computeIfAbsent(session.getCurrentProject(), p -> new OwnerReentrantLock());

 * abused as a cache (i.e. for storing values that can be re-calculated) to avoid memory exhaustion.
 * <p>
 * <strong>Note:</strong> Actual implementations must be thread-safe.
 *
 * @see Session#getData()
 * @since 4.0.0
 */
@Experimental
@ThreadSafe
@Provider
public interface SessionData {

    /**
     * Associates the specified session data with the given key.
     *

            RepositorySystemSession session, ArtifactDescriptorResult artifactDescriptorResult, Model model)
            throws ArtifactDescriptorException {
        Relocations relocations = (Relocations) session.getData()
                .computeIfAbsent(getClass().getName() + ".relocations", () -> parseRelocations(session));
        if (relocations != null) {
            Artifact original = artifactDescriptorResult.getRequest().getArtifact();

    @Nonnull
    Settings getSettings();

    @Nonnull
    LocalRepository getLocalRepository();

    @Nonnull
    List<RemoteRepository> getRemoteRepositories();

    @Nonnull
    SessionData getData();

    /**
     * Returns immutable user properties to use for interpolation. The user properties have been configured directly
     * by the user, e.g. via the {@code -Dkey=value} parameter on the command line.
     *

                if (Features.buildConsumer(request.getUserProperties())) {
                    request.getRepositorySession()
                            .getData()
                            .set(ModelTransformerContext.KEY, transformerContextBuilder.build());
                }

                return results;
            } finally {