holderA.value = 3;
    assertTrue(map.entrySet().contains(Maps.immutableEntry("a", new IntHolder(3))));
    Map<String, Integer> intMap = ImmutableSortedMap.of("a", 3, "b", 2);
    assertEquals(intMap.hashCode(), map.entrySet().hashCode());
    assertEquals(intMap.hashCode(), map.hashCode());
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testViewSerialization() {

    SortedMap<String, Integer> subMap = map.subMap("a", "b");
    assertTrue(subMap instanceof SynchronizedSortedMap);
    assertSame(mutex, ((SynchronizedSortedMap<String, Integer>) subMap).mutex);
  }

  public void testSubMap_K_B_K_B() {
    NavigableMap<String, Integer> map = create();
    NavigableMap<String, Integer> subMap = map.subMap("a", true, "b", false);
    assertTrue(subMap instanceof SynchronizedNavigableMap);

    assertEquals(ImmutableMap.of("banana", 6, "dog", 3), filtered.headMap("emu"));

    assertEquals(ImmutableMap.of("banana", 6), filtered.subMap("banana", "dog"));
    assertEquals(ImmutableMap.of("dog", 3), filtered.subMap("cat", "emu"));

    assertEquals(ImmutableMap.of("dog", 3), filtered.tailMap("cat"));
    assertEquals(ImmutableMap.of("banana", 6, "dog", 3), filtered.tailMap("banana"));
  }

  }

  @Override
  public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
    return new SafeTreeMap<>(
        delegate.subMap(checkValid(fromKey), fromInclusive, checkValid(toKey), toInclusive));
  }

  @Override
  public SortedMap<K, V> subMap(K fromKey, K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

  @Override

  }

  @Override
  public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
    return new SafeTreeMap<>(
        delegate.subMap(checkValid(fromKey), fromInclusive, checkValid(toKey), toInclusive));
  }

  @Override
  public SortedMap<K, V> subMap(K fromKey, K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

  @Override

    TreeBasedTable<String, Integer, Character> table = makeTable();
    populateTable(table);
    return table.rowMap().subMap("b", "x");
  }

  @Override
  protected Map<String, Map<Integer, Character>> makeEmptyMap() {
    return makeTable().rowMap().subMap("b", "x");
  }

  @Override
  protected String getKeyNotInPopulatedMap() {
    return "z";
  }

   * This method returns a {@code ImmutableSortedMap}, consisting of the entries whose keys ranges
   * from {@code fromKey}, inclusive, to {@code toKey}, exclusive.
   *
   * <p>The {@link SortedMap#subMap} documentation states that a submap of a submap throws an {@link
   * IllegalArgumentException} if passed a {@code fromKey} less than an earlier {@code fromKey}.
   * However, this method doesn't throw an exception in that situation, but instead keeps the

    return Maps.keyOrNull(higherEntry(key));
  }

  abstract Iterator<Entry<K, V>> descendingEntryIterator();

  @Override
  public SortedMap<K, V> subMap(@ParametricNullness K fromKey, @ParametricNullness K toKey) {
    return subMap(fromKey, true, toKey, false);
  }

  @Override
  public SortedMap<K, V> headMap(@ParametricNullness K toKey) {
    return headMap(toKey, false);
  }

  @Override

    }

    @Override
    public Entry<K, V>[] createArray(int length) {
      return delegate.createArray(length);
    }
  }

  /** Two bounds (from and to) define how to build a subMap. */
  public enum Bound {
    INCLUSIVE,
    EXCLUSIVE,
    NO_BOUND;
  }

  public static class SortedSetSubsetTestSetGenerator<E extends @Nullable Object>
      implements TestSortedSetGenerator<E> {

    public void clear() {
      standardClear();
    }

    @Override
    public boolean isEmpty() {
      return standardIsEmpty();
    }

    @Override
    public SortedMap<K, V> subMap(K fromKey, K toKey) {
      return standardSubMap(fromKey, toKey);
    }

    @Override
    public @Nullable Entry<K, V> lowerEntry(K key) {
      return standardLowerEntry(key);
    }

    @Override