(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,

  }

  /**
   * A generic {@link Combiner} that lets you use a lambda or method reference to combine two {@link
   * ClosingFuture}s. Use {@link #whenAllSucceed(ClosingFuture, ClosingFuture)} to start this
   * combination.
   *
   * @param <V1> the type returned by the first future
   * @param <V2> the type returned by the second future
   */

   */
  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}.
   *

      super.orderEntriesByValue(valueComparator);
      return this;
    }

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

    /**
     * Returns a newly-created immutable bimap. The iteration order of the returned bimap is the

      return this;
    }

    @CanIgnoreReturnValue
    Builder<E> combine(Builder<E> other) {
      requireNonNull(impl);
      requireNonNull(other.impl);
      /*
       * For discussion of requireNonNull, see the comment on the field.
       *
       * (And I don't believe there's any situation in which we call x.combine(y) when x is a plain

  public void testToImmutableSortedMap_java7_combine() {
    ImmutableSortedMap.Builder<String, Integer> zis =
        ImmutableSortedMap.<String, Integer>naturalOrder().put("one", 1).put("four", 4);
    ImmutableSortedMap.Builder<String, Integer> zat =
        ImmutableSortedMap.<String, Integer>naturalOrder().put("two", 2).put("three", 3);
    ImmutableSortedMap<String, Integer> sortedMap = zis.combine(zat).build();

  public void testToImmutableMap_java7_combine() {
    ImmutableMap.Builder<String, Integer> zis =
        ImmutableMap.<String, Integer>builder().put("one", 1);
    ImmutableMap.Builder<String, Integer> zat =
        ImmutableMap.<String, Integer>builder().put("two", 2).put("three", 3);
    assertMapEquals(zis.combine(zat).build(), "one", 1, "two", 2, "three", 3);
  }

      for (Cell<? extends R, ? extends C, ? extends V> cell : table.cellSet()) {
        put(cell);
      }
      return this;
    }

    @CanIgnoreReturnValue
    Builder<R, C, V> combine(Builder<R, C, V> other) {
      this.cells.addAll(other.cells);
      return this;
    }

    /**
     * Returns a newly-created immutable table.
     *

  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();

        Callable<C> combiner, Executor executor) {
      return new CombinedFuture<>(futures, allMustSucceed, executor, combiner);
    }

    /**
     * Creates the {@link ListenableFuture} which will return the result of running {@code combiner}
     * when all Futures complete. {@code combiner} will run using {@code executor}.
     *