assertThat(set.headSet(2)).containsExactly(1).inOrder();
    assertThat(set.headSet(3)).containsExactly(1, 2).inOrder();
    assertThat(set.headSet(4)).containsExactly(1, 2, 3).inOrder();
    assertThat(set.headSet(Integer.MAX_VALUE)).containsExactly(1, 2, 3).inOrder();
    assertThat(set.headSet(1, true)).containsExactly(1).inOrder();
    assertThat(set.headSet(2, true)).containsExactly(1, 2).inOrder();

    assertThat(set.headSet(2)).containsExactly(1).inOrder();
    assertThat(set.headSet(3)).containsExactly(1, 2).inOrder();
    assertThat(set.headSet(4)).containsExactly(1, 2, 3).inOrder();
    assertThat(set.headSet(Integer.MAX_VALUE)).containsExactly(1, 2, 3).inOrder();
    assertThat(set.headSet(1, true)).containsExactly(1).inOrder();
    assertThat(set.headSet(2, true)).containsExactly(1, 2).inOrder();

    assertThat(multimap.keySet()).containsExactly("foo", "bar", "cow").inOrder();
    assertThat(multimap.removeAll("foo")).containsExactly(6, 7).inOrder();
    assertThat(multimap.keySet()).containsExactly("bar", "cow").inOrder();
    assertTrue(multimap.remove("bar", 4));
    assertThat(multimap.keySet()).containsExactly("bar", "cow").inOrder();
    assertTrue(multimap.remove("bar", 1));

    assertThat(multimap.get("foo")).containsExactly(1, 3, 7).inOrder();
    assertThat(multimap.get("google")).containsExactly(2, 6).inOrder();
    assertThat(multimap.get("tree")).containsExactly(0, 4).inOrder();
  }

  public void testOrderedKeySet() {
    TreeMultimap<String, Integer> multimap = createPopulate();
    assertThat(multimap.keySet()).containsExactly("foo", "google", "tree").inOrder();
  }

    assertThat(elementSet).containsExactly("a", "b", "c", "d", "e", "f").inOrder();
    SortedSet<String> subset = elementSet.subSet("b", "f");
    assertThat(subset).containsExactly("b", "c", "d", "e").inOrder();

    assertTrue(subset.remove("c"));
    assertThat(elementSet).containsExactly("a", "b", "d", "e", "f").inOrder();
    assertThat(subset).containsExactly("b", "d", "e").inOrder();
    assertEquals(10, ms.size());

    assertThat(multimap.keySet()).containsExactly("foo", "bar", "cow").inOrder();
    assertThat(multimap.removeAll("foo")).containsExactly(6, 7).inOrder();
    assertThat(multimap.keySet()).containsExactly("bar", "cow").inOrder();
    assertTrue(multimap.remove("bar", 4));
    assertThat(multimap.keySet()).containsExactly("bar", "cow").inOrder();
    assertTrue(multimap.remove("bar", 1));

    assertThat(multimap.get("foo")).containsExactly(1, 3, 7).inOrder();
    assertThat(multimap.get("google")).containsExactly(2, 6).inOrder();
    assertThat(multimap.get("tree")).containsExactly(0, 4).inOrder();
  }

  public void testOrderedKeySet() {
    TreeMultimap<String, Integer> multimap = createPopulate();
    assertThat(multimap.keySet()).containsExactly("foo", "google", "tree").inOrder();
  }

    assertThat(elementSet).containsExactly("a", "b", "c", "d", "e", "f").inOrder();
    SortedSet<String> subset = elementSet.subSet("b", "f");
    assertThat(subset).containsExactly("b", "c", "d", "e").inOrder();

    assertTrue(subset.remove("c"));
    assertThat(elementSet).containsExactly("a", "b", "d", "e", "f").inOrder();
    assertThat(subset).containsExactly("b", "d", "e").inOrder();
    assertEquals(10, ms.size());

            EndpointPair.unordered(1, 1),
            EndpointPair.unordered(1, 3))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateTShapedGraph() {
    putEdge(2, 1);
    putEdge(1, 4);

            EndpointPair.ordered(1, 3),
            EndpointPair.ordered(1, 2))
        .inOrder();
  }

  /**
   * Populates the graph with nodes and edges in a star shape with node `1` in the middle.
   *
   * <p>Note that the edges are added in a shuffled order to properly test the effect of the
   * insertion order.
   */
  private void populateStarShapedGraph() {
    putEdge(2, 1);
    putEdge(1, 4);