return Arrays.asList(
        new Object[][] {
          {false, false, ElementOrder.insertion(), ElementOrder.insertion()},
          {true, false, ElementOrder.insertion(), ElementOrder.insertion()},
          {false, false, naturalElementOrder, naturalElementOrder},
          {true, true, ElementOrder.insertion(), ElementOrder.insertion()},
        });
  }

  private final boolean allowsSelfLoops;

    return Arrays.asList(
        new Object[][] {
          {false, false, ElementOrder.insertion(), ElementOrder.insertion()},
          {true, false, ElementOrder.insertion(), ElementOrder.insertion()},
          {false, false, naturalElementOrder, naturalElementOrder},
          {true, true, ElementOrder.insertion(), ElementOrder.insertion()},
        });
  }

  private final boolean allowsSelfLoops;

  /**
   * Returns the platform preferred map implementation that preserves insertion order when used only
   * for insertions.
   */
  static <K, V> Map<K, V> preservesInsertionOrderOnPutsMap() {
    return Maps.newLinkedHashMap();
  }

  /**
   * Returns the platform preferred set implementation that preserves insertion order when used only
   * for insertions.
   */
  static <E> Set<E> preservesInsertionOrderOnAddsSet() {

  }

  @Test
  public void nodeOrder_insertion() {
    MutableGraph<Integer> graph = GraphBuilder.directed().nodeOrder(insertion()).build();

    addNodes(graph);

    assertThat(graph.nodeOrder()).isEqualTo(insertion());
    assertThat(graph.nodes()).containsExactly(3, 1, 4).inOrder();
  }

  // The default ordering is INSERTION unless otherwise specified.
  @Test
  public void nodeOrder_default() {

    return this;
  }

  /**
   * Specifies the order of iteration for the elements of {@link Network#nodes()}.
   *
   * <p>The default value is {@link ElementOrder#insertion() insertion order}.
   */
  public <N1 extends N> NetworkBuilder<N1, E> nodeOrder(ElementOrder<N1> nodeOrder) {
    NetworkBuilder<N1, E> newBuilder = cast();
    newBuilder.nodeOrder = checkNotNull(nodeOrder);

  /**
   * Pointer to the predecessor of an entry in insertion order. ENDPOINT indicates a node is the
   * first node in insertion order; all values at indices ≥ {@link #size()} are UNSET.
   */
  @CheckForNull private transient int[] predecessor;

  /**
   * Pointer to the successor of an entry in insertion order. ENDPOINT indicates a node is the last
   * node in insertion order; all values at indices ≥ {@link #size()} are UNSET.
   */

 *
 * @author James Sexton
 */
@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.
   *

    }
  }

  /** If this collection is backed by an array of its elements in insertion order, returns it. */
  Object @Nullable [] internalArray() {
    return null;
  }

  /**
   * If this collection is backed by an array of its elements in insertion order, returns the offset
   * where this collection's elements start.
   */
  int internalArrayStart() {

   * containers with a known order other than insertion order must override this method.
   *
   * <p>Note: This default implementation is overkill (but valid) for an unordered container. An
   * equally valid implementation for an unordered container is to throw an exception. The chosen
   * implementation, however, has the advantage of working for insertion-ordered containers, as
   * well.
   */
  @Override

   * containers with a known order other than insertion order must override this method.
   *
   * <p>Note: This default implementation is overkill (but valid) for an unordered container. An
   * equally valid implementation for an unordered container is to throw an exception. The chosen
   * implementation, however, has the advantage of working for insertion-ordered containers, as
   * well.
   */
  @Override