void testGetRootCause() {
            Exception rootCause = new IllegalStateException("Test root cause");
            TransportException exception = new TransportException("Message", rootCause);

            assertEquals(rootCause, exception.getRootCause());
        }

        @Test
        @DisplayName("Should return null when no root cause")
        void testGetRootCauseWhenNull() {

                }

                root = root.toLowerCase();
                /*
                 * domain-based DFS root shares to links for each
                 */
                final Map<String, CacheEntry<DfsReferralDataInternal>> roots = domains.get(domain);
                if (roots != null) {
                    dr = getLinkReferral(tf, domain, root, path, now, roots);
                }

        /**
         * @param root The root dependency
         * @return this request for chaining, never {@code null}
         */
        @Nonnull
        public DependencyResolverRequestBuilder root(@Nonnull DependencyCoordinates root) {
            this.root = root;
            return this;
        }

        /**

            if (roots != null) {
                SmbTransport trans = null;

                root = root.toLowerCase();

                /* The link entries contain maps of referrals by path representing DFS links.
                 * Note that paths are relative to the root like "\" and not "\example.com\root".
                 */
                CacheEntry links = (CacheEntry) roots.get(root);

        Element root = doc.root();

        // Insert elements with various text content scenarios
        DomUtils.insertContentElement(root, "name", "Test Project Name");
        DomUtils.insertContentElement(root, "description", ""); // Empty content
        DomUtils.insertContentElement(root, "url", null); // Null content
        DomUtils.insertContentElement(root, "inceptionYear", "2023");

    /**
     * Returns an array of {@link Traverser} instances that handle collections of classes or resources based on the specified root package.
     *
     * @param rootPackage
     *            The root package.
     * @return An array of {@link Traverser} instances that handle collections of resources based on the specified root package.
     */
    public static Traverser[] getTraversers(final String rootPackage) {

        Element root = pomDocument.root();

        // Collect all repository containers to process
        Stream<Element> repositoryContainers = Stream.concat(
                // Root level repositories
                Stream.of(
                                root.child(REPOSITORIES).orElse(null),
                                root.child(PLUGIN_REPOSITORIES).orElse(null))

      @Override
      long treeAggregate(@Nullable AvlNode<?> root) {
        return (root == null) ? 0 : root.totalCount;
      }
    },
    DISTINCT {
      @Override
      int nodeAggregate(AvlNode<?> node) {
        return 1;
      }

      @Override
      long treeAggregate(@Nullable AvlNode<?> root) {
        return (root == null) ? 0 : root.distinctElements;
      }
    };

 * </ul>
 *
 * <h4>Full Inference for 4.1.0+ Models</h4>
 * <ul>
 *   <li><strong>ModelVersion Removal</strong>: Removes {@code <modelVersion>} element (inference enabled)</li>
 *   <li><strong>Root Attribute</strong>: Adds {@code root="true"} attribute to root project</li>
 *   <li><strong>Parent Element Trimming</strong>:
 *     <ul>
 *       <li>Removes parent {@code <groupId>} when child has no explicit groupId</li>

            root.attribute("xsi:schemaLocation", newSchemaLocation);
            context.detail("Updated xsi:schemaLocation");
        }
    }

    /**
     * Converts modules to subprojects for 4.1.0 compatibility using domtrip.
     */
    private void convertModulesToSubprojects(Editor editor, UpgradeContext context) {
        Element root = editor.root();
        if (root == null) {
            return;