List<@Nullable Present<V>> localValues = values;
    if (localValues != null) {
      set(combine(localValues));
    }
  }

  @Override
  void releaseResources(ReleaseResourcesReason reason) {
    super.releaseResources(reason);
    this.values = null;
  }

  abstract C combine(List<@Nullable Present<V>> values);

  /** Used for {@link Futures#allAsList} and {@link Futures#successfulAsList}. */

        (Supplier<ImmutableTable.Builder<R, C, V>>) ImmutableTable.Builder::new,
        (builder, t) ->
            builder.put(rowFunction.apply(t), columnFunction.apply(t), valueFunction.apply(t)),
        ImmutableTable.Builder::combine,
        ImmutableTable.Builder::build);
  }

  static <T extends @Nullable Object, R, C, V>
      Collector<T, ?, ImmutableTable<R, C, V>> toImmutableTable(
          Function<? super T, ? extends R> rowFunction,

      super.orderEntriesByValue(valueComparator);
      return this;
    }

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

    @Override
    public ImmutableBiMap<K, V> build() {
      return buildOrThrow();
    }

    @Override

          ImmutableList.Builder::add,
          ImmutableList.Builder::combine,
          ImmutableList.Builder::build);

  private static final Collector<Object, ?, ImmutableSet<Object>> TO_IMMUTABLE_SET =
      Collector.of(
          ImmutableSet::builder,
          ImmutableSet.Builder::add,
          ImmutableSet.Builder::combine,
          ImmutableSet.Builder::build);

  @GwtIncompatible

          ImmutableList.Builder::add,
          ImmutableList.Builder::combine,
          ImmutableList.Builder::build);

  private static final Collector<Object, ?, ImmutableSet<Object>> TO_IMMUTABLE_SET =
      Collector.of(
          ImmutableSet::builder,
          ImmutableSet.Builder::add,
          ImmutableSet.Builder::combine,
          ImmutableSet.Builder::build);

  @GwtIncompatible

  public void testToImmutableSetMultimap_java7_combine() {
    ImmutableSetMultimap.Builder<String, Integer> zis =
        ImmutableSetMultimap.<String, Integer>builder().put("a", 1).put("b", 2);
    ImmutableSetMultimap.Builder<String, Integer> zat =
        ImmutableSetMultimap.<String, Integer>builder().put("a", 3).put("c", 4);
    ImmutableSetMultimap<String, Integer> multimap = zis.combine(zat).build();

   */
  private static final Collector<Object, ?, Optional<Object>> TO_OPTIONAL =
      Collector.of(
          ToOptionalState::new,
          ToOptionalState::add,
          ToOptionalState::combine,
          ToOptionalState::getOptional,
          Collector.Characteristics.UNORDERED);

  /**
   * A collector that converts a stream of zero or one elements to an {@code Optional}.
   *

  <build>
    <resources>
      <resource>
        <directory>..</directory>
        <includes>
          <include>LICENSE</include> <!-- copied from the parent pom because I couldn't figure out a way to make combine.children="append" work -->
          <include>proguard/*</include>
        </includes>
        <targetPath>META-INF</targetPath>
      </resource>
    </resources>
    <plugins>
      <plugin>

  public void testToImmutableBiMap_java7_combine() {
    ImmutableBiMap.Builder<String, Integer> zis =
        ImmutableBiMap.<String, Integer>builder().put("one", 1);
    ImmutableBiMap.Builder<String, Integer> zat =
        ImmutableBiMap.<String, Integer>builder().put("two", 2).put("three", 3);
    ImmutableBiMap<String, Integer> biMap = zis.combine(zat).build();
    assertMapEquals(biMap, "one", 1, "two", 2, "three", 3);

        putAll(entry.getKey(), entry.getValue());
      }
      return this;
    }

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

    /**
     * {@inheritDoc}
     *
     * @since 8.0
     */
    @CanIgnoreReturnValue
    @Override