checkNotNull(nodeU);
    checkNotNull(nodeV);
    return nodes().contains(nodeU) && successors(nodeU).contains(nodeV);
  }

  @Override
  public boolean hasEdgeConnecting(EndpointPair<N> endpoints) {
    checkNotNull(endpoints);
    if (!isOrderingCompatible(endpoints)) {
      return false;
    }
    N nodeU = endpoints.nodeU();
    N nodeV = endpoints.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);

  /**

    for (E key : keys) {
      LockGraphNode node = new LockGraphNode(getLockName(key));
      nodes.add(node);
      map.put(key, node);
    }
    // Pre-populate all allowedPriorLocks with nodes of smaller ordinal.
    for (int i = 1; i < numKeys; i++) {
      nodes.get(i).checkAcquiredLocks(Policies.THROW, nodes.subList(0, i));
    }
    // Pre-populate all disallowedPriorLocks with nodes of larger ordinal.

  public void validateUndirectedEdges() {
    for (Integer node : network.nodes()) {
      new EqualsTester()
          .addEqualityGroup(
              network.inEdges(node), network.outEdges(node), network.incidentEdges(node))
          .testEquals();
      new EqualsTester()
          .addEqualityGroup(
              network.predecessors(node), network.successors(node), network.adjacentNodes(node))
          .testEquals();

    MutableGraph<N> subgraph =
        (nodes instanceof Collection)
            ? GraphBuilder.from(graph).expectedNodeCount(((Collection) nodes).size()).build()
            : GraphBuilder.from(graph).build();
    for (N node : nodes) {
      subgraph.addNode(node);
    }
    for (N node : subgraph.nodes()) {
      for (N successorNode : graph.successors(node)) {

import org.apache.maven.api.annotations.ThreadSafe;

/**
 * An immutable XML node representation that provides a clean API for working with XML data structures.
 * This interface represents a single node in an XML document tree, containing information about
 * the node's name, value, attributes, and child nodes.
 *
 * <p>Example usage:</p>
 * <pre>
 * XmlNode node = XmlNode.newBuilder()
 *     .name("configuration")

      checkArgument(
          edge.length() == 2, "Expecting each edge to consist of 2 characters but got %s", edge);
      char node1 = edge.charAt(0);
      char node2 = edge.charAt(1);
      graphMapBuilder.put(node1, node2);
      if (!directed) {
        graphMapBuilder.put(node2, node1);
      }
    }
    ImmutableMultimap<Character, Character> graphMap = graphMapBuilder.build();

        // nodes must have a single output.
        if (node->num_outputs() != 1) {
          return InvalidArgument(
              "When `num_opers` is set to -1, nodes referenced in `inputs` "
              "must have a single output. Node ",
              node->name(), " has ", node->num_outputs(),
              " outputs. Encountered while creating function '", fn_name, "'");
        }
      }
    }

    for (Integer node : graph.nodes()) {
      new EqualsTester()
          .addEqualityGroup(
              graph.predecessors(node), graph.successors(node), graph.adjacentNodes(node))
          .testEquals();
    }
  }

  @Override
  @Test
  public void nodes_checkReturnedSetMutability() {
    assume().that(graphIsMutable()).isTrue();

    Set<Integer> nodes = graph.nodes();

	nodes := endpoints.GetNodes()
	peers = make([]peerS3Client, len(nodes))
	for i, node := range nodes {
		if node.IsLocal {
			peers[i] = &localPeerS3Client{node: node}
		} else {
			peers[i] = newPeerS3Client(node)
		}
		peers[i].SetPools(node.Pools)
	}

	return peers
}

// Returns a peer S3 client.
func newPeerS3Client(node Node) peerS3Client {