* 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(

  }

  TreeMultimap(Comparator<? super K> keyComparator, Comparator<? super V> valueComparator) {
    super(new TreeMap<K, Collection<V>>(keyComparator));
    this.keyComparator = keyComparator;
    this.valueComparator = valueComparator;
  }

  private TreeMultimap(
      Comparator<? super K> keyComparator,
      Comparator<? super V> valueComparator,
      Multimap<? extends K, ? extends V> multimap) {

      SortedSet<V> valueSet = (SortedSet<V>) valueCollection;
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

  public void testAsMapGetImplementsSortedSet() {
    for (K key : multimap().keySet()) {
      SortedSet<V> valueSet = (SortedSet<V>) multimap().asMap().get(key);
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

      SortedSet<V> valueSet = (SortedSet<V>) valueCollection;
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

  public void testAsMapGetImplementsSortedSet() {
    for (K key : multimap().keySet()) {
      SortedSet<V> valueSet = (SortedSet<V>) multimap().asMap().get(key);
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

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

     * @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);

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SortedSetMultimapGetTester<K, V>
    extends AbstractMultimapTester<K, V, SortedSetMultimap<K, V>> {
  public void testValueComparator() {
    assertEquals(multimap().valueComparator(), multimap().get(k0()).comparator());
  }

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class SortedSetMultimapGetTester<K, V>
    extends AbstractMultimapTester<K, V, SortedSetMultimap<K, V>> {
  public void testValueComparator() {
    assertEquals(multimap().valueComparator(), multimap().get(k0()).comparator());
  }

     *
     * @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) {

      super.putAll(entries);
      return this;
    }

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

    @CanIgnoreReturnValue
    Builder<K, V> combine(Builder<K, V> other) {
      super.combine(other);
      return this;
    }