ValueGraphBuilder.directed()
            .allowsSelfLoops(true)
            .nodeOrder(ElementOrder.<String>natural())
            .<String, Integer>immutable()
            .build();

    assertThat(emptyGraph.isDirected()).isTrue();
    assertThat(emptyGraph.allowsSelfLoops()).isTrue();
    assertThat(emptyGraph.nodeOrder()).isEqualTo(ElementOrder.<String>natural());
  }

  /**

    assertThat(graph.nodeOrder()).isEqualTo(asGraph.nodeOrder());
    assertThat(graph.incidentEdgeOrder()).isEqualTo(asGraph.incidentEdgeOrder());
    assertThat(graph.isDirected()).isEqualTo(asGraph.isDirected());
    assertThat(graph.allowsSelfLoops()).isEqualTo(asGraph.allowsSelfLoops());

    Network<Integer, EndpointPair<Integer>> asNetwork = graph.asNetwork();
    AbstractNetworkTest.validateNetwork(asNetwork);

    assertThat(graph.nodeOrder()).isEqualTo(asGraph.nodeOrder());
    assertThat(graph.incidentEdgeOrder()).isEqualTo(asGraph.incidentEdgeOrder());
    assertThat(graph.isDirected()).isEqualTo(asGraph.isDirected());
    assertThat(graph.allowsSelfLoops()).isEqualTo(asGraph.allowsSelfLoops());

    Network<Integer, EndpointPair<Integer>> asNetwork = graph.asNetwork();
    AbstractNetworkTest.validateNetwork(asNetwork);

  Iterator<N> successorIterator = ImmutableSet.<N>of().iterator();

  static <N> EndpointPairIterator<N> of(BaseGraph<N> graph) {
    return graph.isDirected() ? new Directed<N>(graph) : new Undirected<N>(graph);
  }

  private EndpointPairIterator(BaseGraph<N> graph) {
    this.graph = graph;
    this.nodeIterator = graph.nodes().iterator();
  }

  /**

  private static <N> GraphConnections<N, Presence> connectionsOf(Graph<N> graph, N node) {
    Function<N, Presence> edgeValueFn =
        (Function<N, Presence>) Functions.constant(Presence.EDGE_EXISTS);
    return graph.isDirected()
        ? DirectedGraphConnections.ofImmutable(node, graph.incidentEdges(node), edgeValueFn)
        : UndirectedGraphConnections.ofImmutable(
            Maps.asMap(graph.adjacentNodes(node), edgeValueFn));
  }

        (N successorNode) ->
            // requireNonNull is safe because the endpoint pair comes from the graph.
            requireNonNull(graph.edgeValueOrDefault(node, successorNode, null));
    return graph.isDirected()
        ? DirectedGraphConnections.ofImmutable(
            node, graph.incidentEdges(node), successorNodeToValueFn)
        : UndirectedGraphConnections.ofImmutable(

/** `307 Temporary Redirect` (HTTP/1.1 - RFC 7231)  */
const val HTTP_TEMP_REDIRECT = 307

/** `308 Permanent Redirect` (HTTP/1.1 - RFC 7538)  */
const val HTTP_PERM_REDIRECT = 308

/** `421 Misdirected Request` (HTTP/2 - RFC 7540)  */

   *  * A client timeout (HTTP 408).
   *  * A authorization challenge (HTTP 401 and 407) that is satisfied by the [Authenticator].
   *  * A retryable server failure (HTTP 503 with a `Retry-After: 0` response header).
   *  * A misdirected request (HTTP 421) on a coalesced connection.
   */
  open fun isOneShot(): Boolean = false

  /**
   * Returns the SHA-256 hash of this [RequestBody]
   */
  @Throws(IOException::class)

      MockResponse
        .Builder()
        .body("seed connection")
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .code(421)
        .body("misdirected!")
        .build(),
    )
    server.enqueue(
      MockResponse
        .Builder()
        .body("after misdirect")
        .build(),
    )

    // Seed the connection pool.