}
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<K, V> orderEntriesByValue(Comparator<? super V> valueComparator) {
      checkState(this.valueComparator == null, "valueComparator was already set");
      this.valueComparator = checkNotNull(valueComparator, "valueComparator");
      return this;
    }

    @CanIgnoreReturnValue
    Builder<K, V> combine(Builder<K, V> other) {

   * than all other values, and orders the rest using {@code valueComparator} on the contained
   * value.
   *
   * @since 22.0 (but only since 33.4.0 in the Android flavor)
   */
  public static <T> Comparator<Optional<T>> emptiesFirst(Comparator<? super T> valueComparator) {
    checkNotNull(valueComparator);
    return Comparator.<Optional<T>, @Nullable T>comparing(

      @Nullable Comparator<? super V> valueComparator, Collection<? extends V> values) {
    return (valueComparator == null)
        ? ImmutableSet.copyOf(values)
        : ImmutableSortedSet.copyOf(valueComparator, values);
  }

  private static <V> ImmutableSet<V> emptySet(@Nullable Comparator<? super V> valueComparator) {
    return (valueComparator == null)
        ? ImmutableSet.<V>of()

      @Nullable Comparator<? super V> valueComparator, Collection<? extends V> values) {
    return (valueComparator == null)
        ? ImmutableSet.copyOf(values)
        : ImmutableSortedSet.copyOf(valueComparator, values);
  }

  private static <V> ImmutableSet<V> emptySet(@Nullable Comparator<? super V> valueComparator) {
    return (valueComparator == null)
        ? ImmutableSet.<V>of()

    }

    /**
     * {@inheritDoc}
     *
     * @since 8.0
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
      super.orderValuesBy(valueComparator);
      return this;
    }

    /** Returns a newly-created immutable list multimap. */
    @Override
    public ImmutableListMultimap<K, V> build() {

    assertSame(Ordering.natural(), copyFromSorted.valueComparator());
    assertSame(Ordering.natural(), copyFromSorted.get(1.0).comparator());
  }

  public void testComparators() {
    TreeMultimap<String, Integer> multimap = TreeMultimap.create();
    assertEquals(Ordering.natural(), multimap.keyComparator());
    assertEquals(Ordering.natural(), multimap.valueComparator());
  }

  @J2ktIncompatible

     * @since 19.0
     */
    @CanIgnoreReturnValue
    @Override
    public Builder<K, V> orderEntriesByValue(Comparator<? super V> valueComparator) {
      super.orderEntriesByValue(valueComparator);
      return this;
    }

    @Override
    @CanIgnoreReturnValue
    Builder<K, V> combine(ImmutableMap.Builder<K, V> builder) {
      super.combine(builder);

    assertThat(copy.keySet()).containsExactly(null, "tree", "google").inOrder();
    assertEquals(multimap.keyComparator(), copy.keyComparator());
    assertEquals(multimap.valueComparator(), copy.valueComparator());
  }

     *
     * @since 8.0
     */
    @CanIgnoreReturnValue
    public Builder<K, V> orderValuesBy(Comparator<? super V> valueComparator) {
      this.valueComparator = checkNotNull(valueComparator);
      return this;
    }

    @CanIgnoreReturnValue
    Builder<K, V> combine(Builder<K, V> other) {
      if (other.builderMap != null) {

     * @since 19.0
     */
    @CanIgnoreReturnValue
    public Builder<K, V> orderEntriesByValue(Comparator<? super V> valueComparator) {
      checkState(this.valueComparator == null, "valueComparator was already set");
      this.valueComparator = checkNotNull(valueComparator, "valueComparator");
      return this;
    }

    @CanIgnoreReturnValue
    Builder<K, V> combine(Builder<K, V> other) {