ModelPath childPath = child.getPath();
        if (!getPath().isDirectChild(childPath)) {
            throw new IllegalArgumentException(String.format("Element registration has a path (%s) which is not a child of this node (%s).", childPath, getPath()));
        }

        ModelNodeInternal currentChild = links == null ? null : links.get(childPath.getName());
        if (currentChild != null) {

        Map<Object, Object> hints = new HashMap<>();
        String childPath = child.getProperties().getOrDefault(CHILD_DIRECTORY_PROPERTY, child.getArtifactId());
        hints.put(CHILD_DIRECTORY, childPath);
        hints.put(MavenModelMerger.CHILD_PATH_ADJUSTMENT, getChildPathAdjustment(child, parent, childPath));
        return merger.merge(child, parent, false, hints);
    }

    /**

        ModelPath childPath = modelNode.getPath().child(name);
        final ModelRuleDescriptor descriptor = this.descriptor.append("create()");

        NodeInitializer nodeInitializer = creatorStrategy.initializer(elementType, Specs.<ModelType<?>>satisfyAll());
        ModelRegistration registration = ModelRegistrations.of(childPath, nodeInitializer)
            .descriptor(descriptor)

                return child.getSnapshot(pathInChild, caseSensitivity);
            }

            @Override
            public Optional<MetadataSnapshot> handleAsAncestorOfChild(String childPath, T child) {
                return noChildFoundResult.get();
            }

            @Override
            public Optional<MetadataSnapshot> handleExactMatchWithChild(T child) {

        childSpec.addChildSpecListener((path, spec) -> {
            CopySpecAddress childPath = new DefaultCopySpecAddress(null, DefaultCopySpec.this, additionIndex).append(path);
            fireChildSpecListeners(childPath, spec);
        });

        // Notify upwards of currently existing descendant spec hierarchy

    }

    private static void hasParentProject(def projects, File rootDir, String path, String name, List<String> childPaths) {
        hasProject(projects, rootDir, path, name, null, childPaths)
    }

    private static void hasProject(def projects, File rootDir, String path, String name, String parentPath, List<String> childPaths) {
        def project = projects.find {it.name == name}