final Set<MavenProject> projectsIncludingParents = new HashSet<>();
        for (MavenProject project : session.getProjects()) {
            superPomModels.computeIfAbsent(
                    project.getModelVersion(),
                    v -> superPomProvider.getSuperModel(v).getDelegate());
            boolean isAdded = projectsIncludingParents.add(project);

        for (String key : sessionKeys.keySet()) {
            if (key.contains(".v")) {
                String baseSession = key.substring(0, key.indexOf(".v"));
                sessionArchives.computeIfAbsent(baseSession, k -> new java.util.ArrayList<>()).add(key);
            }
        }

        // Remove old versions
        int removed = 0;

        for (ArtifactRepository repository : repositories) {
            String key = repository.getId();

            List<ArtifactRepository> aliasedRepos = reposByKey.computeIfAbsent(key, k -> new ArrayList<>());

            aliasedRepos.add(repository);
        }

        List<ArtifactRepository> effectiveRepositories = new ArrayList<>();

        for (ArtifactRepository repository : repositories) {
            String key = repository.getId();

            List<ArtifactRepository> aliasedRepos = reposByKey.computeIfAbsent(key, k -> new ArrayList<>());

            aliasedRepos.add(repository);
        }

        List<ArtifactRepository> effectiveRepositories = new ArrayList<>();

      synchronized (mutex) {
        return delegate().replace(key, value);
      }
    }

    @Override
    public V computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) {
      synchronized (mutex) {
        return delegate().computeIfAbsent(key, mappingFunction);
      }
    }

    @SuppressWarnings("nullness") // TODO: b/423853632 - Remove after checker is fixed.
    @Override

            artifacts.put(getKey(spec.artifact), spec);

            String key = spec.artifact.getDependencyConflictId();
            List<ArtifactVersion> artifactVersions = versions.computeIfAbsent(key, k -> new ArrayList<>());
            if (spec.artifact.getVersion() != null) {
                artifactVersions.add(new DefaultArtifactVersion(spec.artifact.getVersion()));
            }
        }

    assertThrows(UnsupportedOperationException.class, () -> unmod.replace(3, "four"));
    assertThrows(
        UnsupportedOperationException.class, () -> unmod.computeIfAbsent(3, k -> k + "three"));
    assertThrows(UnsupportedOperationException.class, () -> unmod.computeIfPresent(4, (k, v) -> v));
    assertThrows(UnsupportedOperationException.class, () -> unmod.compute(4, (k, v) -> v));

                        findLastLocalParentForPluginManagement(context, tempPomPath, pomMap, tempDir, commonRoot);

                if (targetPomForManagement != null) {
                    result.computeIfAbsent(targetPomForManagement, k -> new HashSet<>())
                            .addAll(pluginsNeedingUpgrade);

                    if (!pluginsNeedingUpgrade.isEmpty()) {

            BuildPlanExecutor.attachToThread(step.project);
            session.setCurrentProject(step.project);
        }

        private Clock getClock(Object key) {
            return clocks.computeIfAbsent(key, p -> new Clock());
        }

        private void plan() {
            lock.writeLock().lock();
            try {
                Set<BuildStep> planSteps = plan.allSteps()

            ModelBuilderResult result;
            try {
                ModelTransformer injector = (m, r, p) -> {
                    MavenProject project = projectIndex.computeIfAbsent(m.getId(), f -> new MavenProject());
                    return injectLifecycleBindings(m, r, p, project, request);
                };
                ModelBuilderRequest modelBuildingRequest = getModelBuildingRequest()