populateStarShapedGraph();

    assertThat(graph.edges())
        .containsExactly(
            EndpointPair.ordered(2, 1),
            EndpointPair.ordered(1, 4),
            EndpointPair.ordered(1, 3),
            EndpointPair.ordered(1, 2),
            EndpointPair.ordered(3, 1),
            EndpointPair.ordered(5, 1))
        .inOrder();
  }

  @Test

    this.nodeV = checkNotNull(nodeV);
  }

  /** Returns an {@link EndpointPair} representing the endpoints of a directed edge. */
  public static <N> EndpointPair<N> ordered(N source, N target) {
    return new Ordered<>(source, target);
  }

  /** Returns an {@link EndpointPair} representing the endpoints of an undirected edge. */
  public static <N> EndpointPair<N> unordered(N nodeU, N nodeV) {

    EndpointPair<String> ordered = EndpointPair.ordered("source", "target");
    assertThat(ordered.isOrdered()).isTrue();
    assertThat(ordered).containsExactly("source", "target").inOrder();
    assertThat(ordered.source()).isEqualTo("source");
    assertThat(ordered.target()).isEqualTo("target");
    assertThat(ordered.nodeU()).isEqualTo("source");
    assertThat(ordered.nodeV()).isEqualTo("target");

    EndpointPair<String> ordered = EndpointPair.ordered("source", "target");
    assertThat(ordered.isOrdered()).isTrue();
    assertThat(ordered).containsExactly("source", "target").inOrder();
    assertThat(ordered.source()).isEqualTo("source");
    assertThat(ordered.target()).isEqualTo("target");
    assertThat(ordered.nodeU()).isEqualTo("source");
    assertThat(ordered.nodeV()).isEqualTo("target");

    populateStarShapedGraph();

    assertThat(graph.edges())
        .containsExactly(
            EndpointPair.ordered(2, 1),
            EndpointPair.ordered(1, 4),
            EndpointPair.ordered(1, 3),
            EndpointPair.ordered(1, 2),
            EndpointPair.ordered(3, 1),
            EndpointPair.ordered(5, 1))
        .inOrder();
  }

  @Test

    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(1, 2))).isFalse();
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(2, 1))).isFalse();
  }

  @Test
  public void edgeValue_directed_correct() {
    graph = ValueGraphBuilder.directed().build();
    graph.putEdgeValue(1, 2, "A");
    assertThat(graph.edgeValue(EndpointPair.ordered(1, 2))).hasValue("A");
  }

  @Test

    iter.remove();

    // forward map ordered by currency
    assertThat(bimap.keySet()).containsExactly(Currency.FRANC, Currency.PESO).inOrder();
    // forward map ordered by currency (even for country values)
    assertThat(bimap.values()).containsExactly(Country.SWITZERLAND, Country.CHILE).inOrder();
    // backward map ordered by country
    assertThat(bimap.inverse().keySet())

    iter.remove();

    // forward map ordered by currency
    assertThat(bimap.keySet()).containsExactly(Currency.FRANC, Currency.PESO).inOrder();
    // forward map ordered by currency (even for country values)
    assertThat(bimap.values()).containsExactly(Country.SWITZERLAND, Country.CHILE).inOrder();
    // backward map ordered by country
    assertThat(bimap.inverse().keySet())

    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(1, 2))).isFalse();
    assertThat(graph.hasEdgeConnecting(EndpointPair.ordered(2, 1))).isFalse();
  }

  @Test
  public void edgeValueOrDefault_directed_correct() {
    graph = ValueGraphBuilder.directed().build();
    graph.putEdgeValue(1, 2, "A");
    assertThat(graph.edgeValueOrDefault(EndpointPair.ordered(1, 2), "default")).isEqualTo("A");
  }

  @Test

    assertEquals("toArray(emptyT[]).length:", getNumElements(), array.length);
    expectArrayContentsAnyOrder(createSamplesArray(), array);
  }

  @CollectionFeature.Require(KNOWN_ORDER)
  public void testToArray_emptyArray_ordered() {
    E[] empty = getSubjectGenerator().createArray(0);
    E[] array = collection.toArray(empty);
    assertEquals(
        "toArray(emptyT[]) should return an array of type T", empty.getClass(), array.getClass());