*
     * @return the root node of the dependency graph or {@code null} if none
     */
    @Nullable
    Node getRoot();

    /**
     * The ordered list of the flattened dependency nodes.
     *
     * @return the ordered list of the flattened dependency nodes
     */
    @Nonnull
    List<Node> getNodes();

    /**

        File f = getFileForClasspathResource("canonical-pom.xml");
        MavenProject projectToClone = getProject(f);
        projectToClone.setPomFile(new File(new File(f.getParentFile(), "target"), "flattened.xml"));
        MavenProject clonedProject = projectToClone.clone();
        assertEquals(projectToClone.getFile(), clonedProject.getFile(), "POM file is preserved across clone");
        assertEquals(

            identifiers.put(ident, method);
          }
        }
      }
    }
    return ImmutableList.copyOf(identifiers.values());
  }

  /** Global cache of classes to their flattened hierarchy of supertypes. */
  private static final LoadingCache<Class<?>, ImmutableSet<Class<?>>> flattenHierarchyCache =
      CacheBuilder.newBuilder()
          .weakKeys()
          .build(

    protected String lineSeparator = "\n";

    /** Whether to extract top-level fields as metadata. */
    protected boolean extractMetadata = true;

    /** Prefix for flattened nested keys. */
    protected String nestedKeySeparator = ".";

    /** Maximum number of array elements to extract. */
    protected int maxArrayElements = 100;

    /**
     * Constructs a new JsonExtractor.

 * <p>
 * This builder applies two orthogonal transformations:
 * <ul>
 *   <li><b>Dependency Flattening</b>: When enabled via {@code maven.consumer.pom.flatten=true}, dependency management
 *       is flattened into direct dependencies for non-POM projects, and mixins are removed.</li>
 *   <li><b>Model Version Handling</b>: When {@code preserve.model.version=true} is set, the consumer POM

    /**
     * Shortcut for {@code getService(DependencyResolver.class).flatten(...)}.
     *
     * @param node node for which to get a flattened list
     * @param scope build path scope (main compile, test compile, etc.) of desired nodes
     * @return flattened list of node with the given build path scope

 * followed by <dfn>flattening</dfn> and <dfn>resolution</dfn>.
 * The version selection is done for each dependency during the collection phase.
 * The flatten phase keeps only a single version per ({@code groupId}, {@code artifactId}) pair.
 * The resolution phase actually downloads the dependencies (or artifacts) that have been computed.
 *
 * @since 4.0.0
 */
@Experimental

    /**
     * Should upgrade plugins known to fail with Maven 4 to their minimum compatible versions.
     * This includes upgrading plugins like maven-exec-plugin, maven-enforcer-plugin,
     * flatten-maven-plugin, and maven-shade-plugin to versions that work with Maven 4.
     *
     * @return an {@link Optional} containing the boolean value {@code true} if specified, or empty
     */
    @Nonnull

          <type>String</type>
          <description>pathScope used to flatten dependencies</description>
        </field>
        <field>
          <name>requestType</name>
          <required>false</required>
          <version>2.0.0+</version>
          <type>String</type>
          <description>either {@code collect}, {@code flatten}, or {@code resolve}</description>
        </field>
      </fields>
    </class>

 * <ul>
 *   <li><strong>maven-exec-plugin</strong>: Upgrades to version 3.2.0 or higher</li>
 *   <li><strong>maven-enforcer-plugin</strong>: Upgrades to version 3.0.0 or higher</li>
 *   <li><strong>flatten-maven-plugin</strong>: Upgrades to version 1.2.7 or higher</li>
 *   <li><strong>maven-shade-plugin</strong>: Upgrades to version 3.5.0 or higher</li>