* 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

    @Override
    public NavigableMap<K, V> subMap(
        K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
      synchronized (mutex) {
        return navigableMap(delegate().subMap(fromKey, fromInclusive, toKey, toInclusive), mutex);
      }
    }

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

    @Override
    public NavigableMap<K, V2> subMap(
        @ParametricNullness K fromKey,
        boolean fromInclusive,
        @ParametricNullness K toKey,
        boolean toInclusive) {
      return transformEntries(
          fromMap().subMap(fromKey, fromInclusive, toKey, toInclusive), transformer);
    }

    @Override

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

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