graph = ValueGraphBuilder.directed().incidentEdgeOrder(ElementOrder.unordered()).build();
    assertThat(graph.incidentEdgeOrder()).isEqualTo(ElementOrder.unordered());
  }

  @Test
  public void incidentEdgeOrder_stable() {
    graph = ValueGraphBuilder.directed().incidentEdgeOrder(ElementOrder.stable()).build();
    assertThat(graph.incidentEdgeOrder()).isEqualTo(ElementOrder.stable());
  }

  @Test

    private final MutableGraph<N> mutableGraph;

    Builder(GraphBuilder<N> graphBuilder) {
      // The incidentEdgeOrder for immutable graphs is always stable. However, we don't want to
      // modify this builder, so we make a copy instead.
      this.mutableGraph = graphBuilder.copy().incidentEdgeOrder(ElementOrder.<N>stable()).build();
    }

    /**
     * Adds {@code node} if it is not already present.
     *

      }

      @Override
      public ElementOrder<N> nodeOrder() {
        return AbstractValueGraph.this.nodeOrder();
      }

      @Override
      public ElementOrder<N> incidentEdgeOrder() {
        return AbstractValueGraph.this.incidentEdgeOrder();
      }

      @Override
      public Set<N> adjacentNodes(N node) {
        return AbstractValueGraph.this.adjacentNodes(node);
      }

      @Override

    Builder(ValueGraphBuilder<N, V> graphBuilder) {
      // The incidentEdgeOrder for immutable graphs is always stable. However, we don't want to
      // modify this builder, so we make a copy instead.
      this.mutableValueGraph =
          graphBuilder.copy().incidentEdgeOrder(ElementOrder.<N>stable()).build();
    }

    /**
     * Adds {@code node} if it is not already present.

      }

      @Override
      public ElementOrder<N> nodeOrder() {
        return AbstractValueGraph.this.nodeOrder();
      }

      @Override
      public ElementOrder<N> incidentEdgeOrder() {
        return AbstractValueGraph.this.incidentEdgeOrder();
      }

      @Override
      public Set<N> adjacentNodes(N node) {
        return AbstractValueGraph.this.adjacentNodes(node);
      }

      @Override

    Builder(ValueGraphBuilder<N, V> graphBuilder) {
      // The incidentEdgeOrder for immutable graphs is always stable. However, we don't want to
      // modify this builder, so we make a copy instead.
      this.mutableValueGraph =
          graphBuilder.copy().incidentEdgeOrder(ElementOrder.<N>stable()).build();
    }

    /**
     * Adds {@code node} if it is not already present.

 */
@ElementTypesAreNonnullByDefault
abstract class AbstractGraphBuilder<N> {
  final boolean directed;
  boolean allowsSelfLoops = false;
  ElementOrder<N> nodeOrder = ElementOrder.insertion();
  ElementOrder<N> incidentEdgeOrder = ElementOrder.unordered();

  Optional<Integer> expectedNodeCount = Optional.absent();

  /**
   * Creates a new instance with the specified edge directionality.
   *

      @Override
      public ElementOrder<N> nodeOrder() {
        return AbstractNetwork.this.nodeOrder();
      }

      @Override
      public ElementOrder<N> incidentEdgeOrder() {
        // TODO(b/142723300): Return AbstractNetwork.this.incidentEdgeOrder() once Network has that
        //   method.
        return ElementOrder.unordered();
      }

      @Override
      public boolean isDirected() {

      @Override
      public ElementOrder<N> nodeOrder() {
        return AbstractNetwork.this.nodeOrder();
      }

      @Override
      public ElementOrder<N> incidentEdgeOrder() {
        // TODO(b/142723300): Return AbstractNetwork.this.incidentEdgeOrder() once Network has that
        //   method.
        return ElementOrder.unordered();
      }

      @Override
      public boolean isDirected() {

            && nodes().contains(endpointPair.nodeU())
            && successors((N) endpointPair.nodeU()).contains(endpointPair.nodeV());
      }
    };
  }

  @Override
  public ElementOrder<N> incidentEdgeOrder() {
    return ElementOrder.unordered();
  }

  @Override
  public Set<EndpointPair<N>> incidentEdges(N node) {
    checkNotNull(node);