throw new UnsupportedOperationException();
    }

    @Override
    public NodeIterator childIterator(NodeTest test, boolean reverse, NodePointer startWith) {
        return new Xpp3DomNodeIterator(this, test, reverse, startWith);
    }

    @Override
    public NodeIterator attributeIterator(QName qname) {
        return new Xpp3DomAttributeIterator(this, qname);
    }

import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.apache.maven.api.xml.XmlNode;
import org.codehaus.plexus.util.xml.Xpp3Dom;

/**
 * A node iterator for JXPath to support <code>Xpp3Dom</code>.
 *
 */
class Xpp3DomNodeIterator implements NodeIterator {

    private NodePointer parent;

    private NodeTest test;

import org.apache.commons.jxpath.ri.QName;
import org.apache.commons.jxpath.ri.model.NodeIterator;
import org.apache.commons.jxpath.ri.model.NodePointer;
import org.apache.maven.api.xml.XmlNode;

/**
 * An attribute iterator for JXPath to support <code>Xpp3Dom</code>.
 *
 */
class Xpp3DomAttributeIterator implements NodeIterator {

    private NodePointer parent;

    private XmlNode node;

  }

  /** An {@code Iterator} over all nodes. */
  private final class NodeIterator implements ListIterator<Entry<K, V>> {
    int nextIndex;
    @Nullable Node<K, V> next;
    @Nullable Node<K, V> current;
    @Nullable Node<K, V> previous;
    int expectedModCount = modCount;

    NodeIterator(int index) {
      int size = size();
      checkPositionIndex(index, size);