this.trace = trace;
    }

    @Nonnull
    @Override
    public S getSession() {
        return session;
    }

    @Override
    public RequestTrace getTrace() {
        return trace;
    }

            RepositorySystemSession session, ArtifactDescriptorRequest request, ArtifactDescriptorResult result)
            throws ArtifactDescriptorException {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

        LinkedHashSet<String> visited = new LinkedHashSet<>();
        for (Artifact a = request.getArtifact(); ; ) {
            Artifact pomArtifact = ArtifactDescriptorUtils.toPomArtifactUnconditionally(a);

     * hierarchy and can carry additional diagnostic information.
     *
     * @return the request trace, or {@code null} if no trace information is available
     */
    @Nullable
    RequestTrace getTrace();

    /**
     * Returns a hashcode value for this request, based on all significant fields.
     * Implementations must ensure that if two requests are equal according to

        ArtifactInstallerRequest request =
                ArtifactInstallerRequest.builder().session(session).trace(trace).build();

        assertEquals(trace, request.getTrace());
        assertEquals(session, request.getSession());
    }

    @Test
    void testDependencyResolverRequestEquality() {
        Session session = mock(Session.class);

            VersionRangeResult result,
            VersionRangeRequest request,
            Metadata.Nature wantedNature) {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

        Map<String, ArtifactRepository> versionIndex = new HashMap<>();

        Metadata metadata = new DefaultMetadata(
                request.getArtifact().getGroupId(),

    @Override
    public VersionResult resolveVersion(RepositorySystemSession session, VersionRequest request)
            throws VersionResolutionException {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

        Artifact artifact = request.getArtifact();

        String version = artifact.getVersion();

        VersionResult result = new VersionResult(request);

        Key cacheKey = null;

        requireNonNull(event, "event cannot be null");

        if (!isLocalRepositoryArtifactOrMissing(event.getSession(), event.getArtifact())) {
            return;
        }

        RequestTrace trace = event.getTrace();

        CollectStepData collectStepTrace = null;
        ArtifactRequest artifactRequest = null;
        ArtifactDescriptorRequest artifactDescriptorRequest = null;
        Plugin plugin = null;

        ModelBuilderRequestBuilder() {}

        ModelBuilderRequestBuilder(ModelBuilderRequest request) {
            this.session = request.getSession();
            this.trace = request.getTrace();
            this.requestType = request.getRequestType();
            this.locationTracking = request.isLocationTracking();
            this.recursive = request.isRecursive();
            this.source = request.getSource();

                request.addDependency(pluginDep);
            }

            DependencyRequest depRequest = new DependencyRequest(request, resolutionFilter);
            depRequest.setTrace(trace.trace());

            request.setTrace(RequestTrace.newChild(trace.trace(), depRequest));

            node = repoSystem.collectDependencies(pluginSession, request).getRoot();

            if (logger.isDebugEnabled()) {

            try {
                ArtifactRequest request = new ArtifactRequest(pomArtifact, repositories, context);
                request.setTrace(trace);
                pomArtifact = resolver.resolveArtifact(session, request).getArtifact();
            } catch (ArtifactResolutionException e) {