DomUtils.insertContentElement(customParent, "newChild", "new value");

        String xmlOutput = DomUtils.toXml(doc);

        // Should be appended at the end since no ordering is defined for customParent
        assertTrue(xmlOutput.contains("<newChild>new value</newChild>"), "Should contain new child element");

        public org.w3c.dom.Document getOwnerDocument() {
            return null;
        }

        @Override
        public Node insertBefore(Node newChild, Node refChild) {
            return null;
        }

        @Override
        public Node replaceChild(Node newChild, Node oldChild) {
            return null;
        }

        @Override
        public Node removeChild(Node oldChild) {

            RepositorySystemSession session,
            VersionRangeResult result,
            VersionRangeRequest request,
            Metadata.Nature wantedNature) {
        RequestTrace trace = RequestTrace.newChild(request.getTrace(), request);

        Map<String, ArtifactRepository> versionIndex = new HashMap<>();

        Metadata metadata = new DefaultMetadata(
                request.getArtifact().getGroupId(),