.put("one", "uno", 1)
                .put("two", "dos", 6)
                .put("three", "tres", 3)
                .build(),
            immutableCell("one", "uno", 1),
            immutableCell("two", "dos", 2),
            immutableCell("three", "tres", 3),
            immutableCell("two", "dos", 4));
  }

  public void testToImmutableTableMergingNullRowKey() {

    assertMapEquals(ImmutableSortedMap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMapEquals(
        ImmutableSortedMap.of("one", 1, "two", 2, "three", 3), "one", 1, "three", 3, "two", 2);
    assertMapEquals(
        ImmutableSortedMap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "four",
        4,
        "one",
        1,
        "three",
        3,
        "two",
        2);
    assertMapEquals(

        .containsExactly(mapEntry("three", 5), mapEntry("two", 3))
        .inOrder();
    assertThat(map.subMap("one", "two").entrySet())
        .containsExactly(mapEntry("one", 3), mapEntry("three", 5))
        .inOrder();

    assertEquals(ImmutableSortedMap.of("two", 3, "three", 5), map.tailMap("three", true));
    assertEquals(ImmutableSortedMap.of("one", 3, "three", 5), map.headMap("two", false));

        .containsExactly(mapEntry("three", 5), mapEntry("two", 3))
        .inOrder();
    assertThat(map.subMap("one", "two").entrySet())
        .containsExactly(mapEntry("one", 3), mapEntry("three", 5))
        .inOrder();

    assertEquals(ImmutableSortedMap.of("two", 3, "three", 5), map.tailMap("three", true));
    assertEquals(ImmutableSortedMap.of("one", 3, "three", 5), map.headMap("two", false));

   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *
   * @throws IllegalArgumentException if two keys have the same value or two values have the same
   *     key
   * @throws NullPointerException if any key or value in {@code map} is null
   */
  public static <K, V> ImmutableBiMap<K, V> copyOf(Map<? extends K, ? extends V> map) {

    assertMultimapEquals(ImmutableListMultimap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMultimapEquals(
        ImmutableListMultimap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMultimapEquals(
        ImmutableListMultimap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,
        "three",
        3,
        "four",

    assertMultimapEquals(ImmutableSetMultimap.of("one", 1, "two", 2), "one", 1, "two", 2);
    assertMultimapEquals(
        ImmutableSetMultimap.of("one", 1, "two", 2, "three", 3), "one", 1, "two", 2, "three", 3);
    assertMultimapEquals(
        ImmutableSetMultimap.of("one", 1, "two", 2, "three", 3, "four", 4),
        "one",
        1,
        "two",
        2,
        "three",
        3,
        "four",

   * equal to the element that preceded it, according to the specified comparator. Note that this is
   * always true when the iterable has fewer than two elements.
   */
  public static <T extends @Nullable Object> boolean isInOrder(
      Iterable<? extends T> iterable, Comparator<T> comparator) {
    checkNotNull(comparator);
    Iterator<? extends T> it = iterable.iterator();

    Object one = new Object();
    Object two = new Object();
    Object three = new Object();
    Object four = new Object();
    Object five = new Object();
    Object six = new Object();

    map.put(one, two);
    map.remove(one);
    assertNotified(listener, one, two, RemovalCause.EXPLICIT);

    map.put(two, three);
    map.remove(two, three);

    Object one = new Object();
    Object two = new Object();
    Object three = new Object();
    Object four = new Object();
    Object five = new Object();
    Object six = new Object();

    map.put(one, two);
    map.remove(one);
    assertNotified(listener, one, two, RemovalCause.EXPLICIT);

    map.put(two, three);
    map.remove(two, three);