/** Returns the children of the specified node. Must not contain null. */
  public abstract Iterable<T> children(T root);

  /**
   * Returns an unmodifiable iterable over the nodes in a tree structure, using pre-order traversal.
   * That is, each node's subtrees are traversed after the node itself is returned.
   *
   * <p>No guarantees are made about the behavior of the traversal when nodes change while iteration

        writeElastisearchJsonApi(zos, id, "nodes", "stats");
        writeElastisearchJsonApi(zos, id, "nodes", "_all");
        writeElastisearchJsonApi(zos, id, "nodes", "usage");
        writeElastisearchJsonApi(zos, id, "remote", "info");
        writeElastisearchJsonApi(zos, id, "tasks", "");
        writeElastisearchJsonApi(zos, id, "nodes", "hot_threads");
    }

     *
     * @param tree "dirty" tree root
     * @param versionedVertices true if graph nodes should be versioned (different versions -> different nodes)
     * @param scopedVertices true if graph nodes should be versioned and scoped
     * (different versions and/or scopes -> different nodes)
     *
     */
    public MetadataGraph(MetadataTreeNode tree, boolean versionedVertices, boolean scopedVertices)

import java.util.List;

/**
 * MetadataGraph node - as it's a directed graph - holds adjacency lists for incident and exident nodes
 *
 *
 */
@Deprecated
public class MetadataGraphNode {
    /** node payload */
    MavenArtifactMetadata metadata;

    /** nodes, incident to this (depend on me) */
    List<MetadataGraphNode> inNodes;

    /** nodes, exident to this (I depend on) */

        nodes.add(node);
    }

    /**
     * find a node by the GAV (metadata)
     *
     * @param md
     */
    public MetadataGraphNode findNode(MavenArtifactMetadata md) {
        for (MetadataGraphNode mgn : nodes) {
            if (mgn.metadata.equals(md)) {
                return mgn;
            }
        }

        MetadataGraphNode node = new MetadataGraphNode(md);
        addNode(node);

   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}, and to
   * {@code edgeConnectingOrNull(nodeU, nodeV) != null}.
   *
   * <p>In an undirected network, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**

  int outDegree(N node);

  /**
   * Returns true if there is an edge that directly connects {@code nodeU} to {@code nodeV}. This is
   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}.
   *
   * <p>In an undirected graph, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  @Override
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**

  int outDegree(N node);

  /**
   * Returns true if there is an edge that directly connects {@code nodeU} to {@code nodeV}. This is
   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}.
   *
   * <p>In an undirected graph, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  @Override
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**

  int outDegree(N node);

  /**
   * Returns true if there is an edge that directly connects {@code nodeU} to {@code nodeV}. This is
   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}.
   *
   * <p>In an undirected graph, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  @Override
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**

   * equivalent to {@code nodes().contains(nodeU) && successors(nodeU).contains(nodeV)}, and to
   * {@code edgeConnectingOrNull(nodeU, nodeV) != null}.
   *
   * <p>In an undirected network, this is equal to {@code hasEdgeConnecting(nodeV, nodeU)}.
   *
   * @since 23.0
   */
  boolean hasEdgeConnecting(N nodeU, N nodeV);

  /**