return s.get();
        } else {
            return cache.computeIfAbsent(groupId, artifactId, version, tag, s);
        }
    }

    private static <T> T cache(ModelCache cache, Source source, String tag, Callable<T> supplier) {
        Supplier<T> s = asSupplier(supplier);
        if (cache == null) {
            return s.get();
        } else {

        if (!hasBeenPackagedDuringThisSession(project)) {
            // fallback to loose class files only if artifacts haven't been packaged yet
            // and only for plain old jars. Not war files, not ear files, not anything else.
            return determineBuildOutputDirectoryForArtifact(project, artifact);
        }

        // The fall-through indicates that the artifact cannot be found;

                Path path = artifactManager.getPath(artifact).orElse(null);
                if (path != null) {
                    paths.put(artifact, path);
                } else {
                    requests.add(new ArtifactRequest(aetherArtifact, repositories, null));
                }
            }
            if (!requests.isEmpty()) {
                List<ArtifactResult> results =

        if (modelSource instanceof FileModelSource fms) {
            return ModelSource.fromPath(fms.getPath());
        } else if (modelSource instanceof ArtifactModelSource ams) {
            return ModelSource.fromPath(ams.getPath(), ams.toString());
        } else {
            return new ModelSource() {
                @Override
                public ModelSource resolve(ModelLocator modelLocator, String relative) {

        String originalPackaging = project.getOriginalModel().getPackaging();
        if (POM_PACKAGING.equals(packaging) && !BOM_PACKAGING.equals(originalPackaging)) {
            return buildPom(session, project, src);
        } else {
            return buildNonPom(session, project, src);
        }
    }

    protected Model buildPom(RepositorySystemSession session, MavenProject project, Path src)
            throws ModelBuilderException {

        if (repositoryCache == null) {
            return new DefaultModelCache(new ConcurrentHashMap<>());
        } else {
            if (anew) {
                cache = new ConcurrentHashMap<>();
                repositoryCache.put(session, KEY, cache);
            } else {
                cache = (ConcurrentHashMap<Object, Supplier<?>>)

                    }
                    projects.add(projectBuilder.build(modulePom, configuration).getProject());
                }
            }
        } else {
            MavenProject project = createStubMavenProject();
            project.setRemoteArtifactRepositories(request.getRemoteRepositories());

                        null,
                        "must be unique but found duplicate declaration of plugin " + key,
                        plugin);
            } else {
                index.put(key, plugin);
            }

            Set<String> executionIds = new HashSet<>();

            for (PluginExecution exec : plugin.getExecutions()) {

            pomRepositories = pomRepositories.stream()
                    .filter(r -> !ids.contains(r.getId()))
                    .toList();
        } else {
            Set<String> ids =
                    pomRepositories.stream().map(RemoteRepository::getId).collect(Collectors.toSet());
            repos = repos.stream().filter(r -> !ids.contains(r.getId())).toList();
        }

        if (repositories != null) {
            return repositories;
        } else if (resolverRepositories != null) {
            return map(resolverRepositories, DefaultRemoteRepository::new);
        } else {
            throw new IllegalArgumentException("no remote repositories provided");
        }
    }

    @Nonnull
    @Override