* builds an empty map.
     *
     * <p>If the {@code resolve} parameter value is {@code false}, then some or all map values may
     * be null instead of the actual module name. This option can avoid the cost of reading module
     * descriptors when only the modules existence needs to be verified.</p>
     *
     * <p><b>Algorithm:</b>
     * If the given path is a directory, then there is a choice:
     * </p>

        List<MetadataGeneratorFactory> factories = plexusContainer.lookupList(MetadataGeneratorFactory.class);
        assertNotNull(factories);
        factories.forEach(f -> System.out.println(f.getClass().getName()));
        assertEquals(3, factories.size());
    }

    @Test
    void testProjectDependencies() {

        if (extensionRecord == null) {
            ClassRealm extensionRealm = classRealmManager.createExtensionRealm(plugin, toAetherArtifacts(artifacts));

            // TODO figure out how to use the same PluginDescriptor when running mojos

            PluginDescriptor pluginDescriptor = null;
            if (plugin.isExtensions() && !artifacts.isEmpty()) {

     */
    @Nonnull
    RemoteRepository createRemoteRepository(@Nonnull Repository repository);

    /**
     * Creates a coordinate out of string that is formatted like:
     * {@code <groupId>:<artifactId>[:<extension>[:<classifier>]]:<version>}.
     * <p>
     * Shortcut for {@code getService(ArtifactFactory.class).create(...)}.
     *

        MojoExecution exec = newMojoExecution(session);

        Object result =
                new PluginParameterExpressionEvaluatorV4(session, null, exec).evaluate("${mojo.plugin.descriptor}");

        System.out.println("Result: " + result);

        assertSame(
                exec.getPlugin().getDescriptor(),
                result,
                "${mojo.plugin.descriptor} expression does not return plugin descriptor.");

        MojoExecution exec = newMojoExecution();

        MavenSession session = newMavenSession();

        Object result = new PluginParameterExpressionEvaluator(session, exec).evaluate("${plugin}");

        System.out.println("Result: " + result);

        assertSame(
                exec.getMojoDescriptor().getPluginDescriptor(),
                result,
                "${plugin} expression does not return plugin descriptor.");
    }

  a server container in-JVM, running tests against it, and shutting it down.

** SCM mojos

  See below for discussion on SCM-related operations. Any mojo which
  carries out some analysis or other interaction with a SCM system
  will likely be unavailable when in offline mode.


* Implications for Subsystems

** Maven-Wagon

                        .resumeFrom(MODULE_B)
                        .expectResult(MODULE_B, MODULE_C_2),
                scenario("Duplicate projects are filtered out")
                        .activeRequiredProjects(MODULE_A, MODULE_A)
                        .expectResult(MODULE_A),
                scenario("Select reactor by specific pom")
                        .requestedPom(MODULE_C)

     * builds an empty map.
     *
     * <p>If the {@code resolve} parameter value is {@code false}, then some or all map values may
     * be null instead of the actual module name. This option can avoid the cost of reading module
     * descriptors when only the modules existence needs to be verified.</p>
     *
     * <p><b>Algorithm:</b>
     * If the given path is a directory, then there is a choice:
     * </p>

     * @param root the root node of the dependency graph
     * @param count estimated number of dependencies
     */
    DefaultDependencyResolverResult(List<Exception> exceptions, Node root, int count) {
        this.exceptions = exceptions;
        this.root = root;
        nodes = new ArrayList<>(count);
        paths = new ArrayList<>(count);
        dispatchedPaths = new LinkedHashMap<>();