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;

    private XmlNode node;

    private List<XmlNode> children;

    private List<XmlNode> filteredChildren = new ArrayList<>();

   * self-loops twice (equivalently, the number of times an edge touches {@code node}).
   *
   * <p>For directed networks, this is equal to {@code inDegree(node) + outDegree(node)}.
   *
   * <p>For undirected networks, this is equal to {@code incidentEdges(node).size()} + (number of
   * self-loops incident to {@code node}).
   *

      node = root.ceiling(comparator(), endpoint);
      if (node == null) {
        return null;
      }
      if (range.getLowerBoundType() == BoundType.OPEN
          && comparator().compare(endpoint, node.getElement()) == 0) {
        node = node.succ();
      }
    } else {
      node = header.succ();
    }
    return (node == header || !range.contains(node.getElement())) ? null : node;
  }

   */
  Set<E> edgesConnecting(N node);

  /**
   * Returns the node that is adjacent to the origin node along {@code edge}.
   *
   * <p>In the directed case, {@code edge} is assumed to be an outgoing edge.
   */
  N adjacentNode(E edge);

  /**
   * Remove {@code edge} from the set of incoming edges. Returns the former predecessor node.
   *
   * <p>In the undirected case, returns {@code null} if {@code isSelfLoop} is true.

* etc.

Nesses casos, você normalmente retornaria um **HTTP status code** próximo ao status code na faixa do status code **400** (do 400 ao 499).

Isso é bastante similar ao caso do HTTP status code 200 (do 200 ao 299). Esses "200" status codes significam que, de algum modo, houve sucesso na requisição.

Os status codes na faixa dos 400 significam que houve um erro por parte do cliente.

     */
    boolean enter(@Nonnull Node node);

    /**
     * Ends the visit to the specified dependency node.
     *
     * @param node the dependency node to visit
     * @return <code>true</code> to visit the specified dependency node's next sibling, <code>false</code> to skip the
     *         specified dependency node's next siblings and proceed to its parent
     */
    boolean leave(@Nonnull Node node);

   */
  private void removeNode(Node<K, V> node) {
    if (node.previous != null) {
      node.previous.next = node.next;
    } else { // node was head
      head = node.next;
    }
    if (node.next != null) {
      node.next.previous = node.previous;
    } else { // node was tail
      tail = node.previous;
    }
    if (node.previousSibling == null && node.nextSibling == null) {
      /*

  /**
   * Returns the value associated with the edge connecting the origin node to {@code node}, or null
   * if there is no such edge.
   */
  @Nullable V value(N node);

  /** Remove {@code node} from the set of predecessors. */
  void removePredecessor(N node);

  /**
   * Remove {@code node} from the set of successors. Returns the value previously associated with
   * the edge connecting the two nodes.

 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)
 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a

 * matches the insertion order. All optional operations (adding and removing) are supported. All
 * elements, including {@code null}, are permitted.
 *
 * <p>{@code contains(x)}, {@code add(x)} and {@code remove(x)}, are all (expected and amortized)
 * constant time operations. Expected in the hashtable sense (depends on the hash function doing a