}

    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    if (connectionsU == null) {
      connectionsU = addNodeInternal(nodeU);
    }
    V previousValue = connectionsU.addSuccessor(nodeV, value);
    GraphConnections<N, V> connectionsV = nodeConnections.get(nodeV);
    if (connectionsV == null) {
      connectionsV = addNodeInternal(nodeV);
    }

    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    return (connectionsU != null) && connectionsU.successors().contains(nodeV);
  }

  @CheckForNull
  private final V edgeValueOrDefaultInternal(N nodeU, N nodeV, @CheckForNull V defaultValue) {
    GraphConnections<N, V> connectionsU = nodeConnections.get(nodeU);
    V value = (connectionsU == null) ? null : connectionsU.value(nodeV);

              orderedNodeConnections.iterator(),
              (NodeConnection<N> connection) -> {
                if (connection instanceof NodeConnection.Succ) {
                  return EndpointPair.ordered(thisNode, connection.node);
                } else {
                  return EndpointPair.ordered(connection.node, thisNode);
                }
              });
    }

  }

  final NetworkConnections<N, E> checkedConnections(N node) {
    NetworkConnections<N, E> connections = nodeConnections.get(node);
    if (connections == null) {
      checkNotNull(node);
      throw new IllegalArgumentException(String.format(NODE_NOT_IN_GRAPH, node));
    }
    return connections;
  }

  final N checkedReferenceNode(E edge) {
    N referenceNode = edgeToReferenceNode.get(edge);

 *
 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6
 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY}
 * socket option on an IPv6 socket). Yes, it's confusing. Nevertheless, these "mapped" addresses
 * were never supposed to be seen on the wire. That assumption was dropped, some say mistakenly, in

      <name>Apache License, Version 2.0</name>
      <url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
      <distribution>repo</distribution>
    </license>
  </licenses>
  <scm>
    <connection>scm:git:https://github.com/google/guava.git</connection>
    <developerConnection>scm:git:******@****.***:google/guava.git</developerConnection>
    <url>https://github.com/google/guava</url>
  </scm>
  <developers>
    <developer>

  /** The HTTP {@code Authorization} header field name. */
  public static final String AUTHORIZATION = "Authorization";
  /** The HTTP {@code Connection} header field name. */
  public static final String CONNECTION = "Connection";
  /** The HTTP {@code Cookie} header field name. */
  public static final String COOKIE = "Cookie";
  /**