*       </ul>
   * </ul>
   *
   * @since 29.0
   */
  public static <S> ElementOrder<S> stable() {
    return new ElementOrder<>(Type.STABLE, null);
  }

  /** Returns an instance which specifies that insertion ordering is guaranteed. */
  public static <S> ElementOrder<S> insertion() {
    return new ElementOrder<>(Type.INSERTION, null);
  }

  /**

   *       </ul>
   * </ul>
   *
   * @since 29.0
   */
  public static <S> ElementOrder<S> stable() {
    return new ElementOrder<>(Type.STABLE, null);
  }

  /** Returns an instance which specifies that insertion ordering is guaranteed. */
  public static <S> ElementOrder<S> insertion() {
    return new ElementOrder<>(Type.INSERTION, null);
  }

  /**

    assertThat(network.edgeOrder()).isEqualTo(ElementOrder.insertion());
    assertThat(network.edges()).containsExactly("i", "e", "p").inOrder();
    assertThat(network.nodeOrder()).isEqualTo(ElementOrder.insertion()); // default
  }

  @Test
  public void edgeOrder_natural() {
    MutableNetwork<Integer, String> network =
        NetworkBuilder.directed().edgeOrder(ElementOrder.<String>natural()).build();

  public static Collection<Object[]> parameters() {
    ElementOrder<?> naturalElementOrder = ElementOrder.sorted(Ordering.natural());

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

    assertThat(immutableValueGraph.incidentEdgeOrder()).isEqualTo(ElementOrder.stable());
  }

  @Test
  public void incidentEdgeOrder_fromUnorderedGraph_stable() {
    ImmutableValueGraph<String, Integer> immutableValueGraph =
        ImmutableValueGraph.copyOf(
            ValueGraphBuilder.directed()
                .incidentEdgeOrder(ElementOrder.unordered())
                .<String, Integer>build());

      ElementOrder<N1> incidentEdgeOrder) {
    checkArgument(
        incidentEdgeOrder.type() == ElementOrder.Type.UNORDERED
            || incidentEdgeOrder.type() == ElementOrder.Type.STABLE,
        "The given elementOrder (%s) is unsupported. incidentEdgeOrder() only supports"
            + " ElementOrder.unordered() and ElementOrder.stable().",
        incidentEdgeOrder);

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

  private final boolean allowsSelfLoops;
  private final ElementOrder<Integer> incidentEdgeOrder;

  public StandardMutableUndirectedGraphTest(

        GraphBuilder.directed()
            .allowsSelfLoops(true)
            .nodeOrder(ElementOrder.<String>natural())
            .immutable()
            .build();

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

  /**

        GraphBuilder.directed()
            .allowsSelfLoops(true)
            .nodeOrder(ElementOrder.<String>natural())
            .immutable()
            .build();

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

  /**

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

  private final boolean allowsSelfLoops;
  private final ElementOrder<Integer> incidentEdgeOrder;

  public StandardMutableUndirectedGraphTest(