path = defaultArtifact.getArtifact().getPath();
        }
        return Optional.ofNullable(path);
    }

    @Override
    public void setPath(@Nonnull ProducedArtifact artifact, Path path) {
        String id = id(requireNonNull(artifact, "artifact cannot be null"));
        if (session.getMavenSession().getAllProjects() != null) {

                (et, vl) -> ((ThumbnailQueue) et).setGenerator(DfTypeUtil.toString(vl)), "generator");
        setupEpg(_epgMap, et -> ((ThumbnailQueue) et).getPath(), (et, vl) -> ((ThumbnailQueue) et).setPath(DfTypeUtil.toString(vl)),
                "path");
        setupEpg(_epgMap, et -> ((ThumbnailQueue) et).getTarget(), (et, vl) -> ((ThumbnailQueue) et).setTarget(DfTypeUtil.toString(vl)),
                "target");

        final YamlFrontMatterVisitor visitor = new YamlFrontMatterVisitor();
        document.accept(visitor);

        final Map<String, List<String>> frontMatter = visitor.getData();
        for (final Map.Entry<String, List<String>> entry : frontMatter.entrySet()) {
            final String key = "frontmatter." + entry.getKey();
            final List<String> values = entry.getValue();

            result.setCreatedTime(DfTypeUtil.toLong(source.get("createdTime")));
            result.setGenerator(DfTypeUtil.toString(source.get("generator")));
            result.setPath(DfTypeUtil.toString(source.get("path")));
            result.setTarget(DfTypeUtil.toString(source.get("target")));
            result.setThumbnailId(DfTypeUtil.toString(source.get("thumbnail_id")));

        .build()
    assertThat(headers["Test-Instant"]).isEqualTo("Thu, 01 Jan 1970 00:00:00 GMT")
    assertThat(headers.getInstant("Test-Instant")).isEqualTo(expected)
  }

  @Test fun setDate() {
    val expected = Date(1000)
    val headers =
      Headers
        .Builder()
        .add("testDate", Date(0L))
        .set("testDate", expected)
        .build()

        boolean halted;
        // The ReactorBuildStatus is only available if the SmartBuilder is used
        ReactorBuildStatus status =
                (ReactorBuildStatus) session.getRepositorySession().getData().get(ReactorBuildStatus.class);
        if (status != null) {
            halted = status.isHalted();
        } else {
            // assume sensible default
            Throwable t = projectExecutionEvent.getCause();

            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());

            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();

                                }
                                return Optional.ofNullable(path);
                            }

                            @Override
                            public void setPath(ProducedArtifact artifact, Path path) {
                                paths.put(artifact.key(), path);
                            }
                        })),
                null);

 * 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.
     *