return CartesianSet.create(sets);
  }

  /**
   * Returns every possible list that can be formed by choosing one element from each of the given
   * sets in order; the "n-ary <a href="http://en.wikipedia.org/wiki/Cartesian_product">Cartesian
   * product</a>" of the sets. For example:
   *
   * <pre>{@code
   * Sets.cartesianProduct(

    checkHashCode(Sets.cartesianProduct(set(num), mt));
    checkHashCode(Sets.cartesianProduct(set(num), set(1)));
    checkHashCode(Sets.cartesianProduct(set(1), set(2, num)));
    checkHashCode(Sets.cartesianProduct(set(1, num), set(2, num - 1)));
    checkHashCode(Sets.cartesianProduct(set(1, num), set(2, num - 1), set(3, num + 1)));

    // a bigger one
    checkHashCode(

    assertThat(map.entrySet())
        .containsExactly(mapEntry("one", 3), mapEntry("two", 3), mapEntry("three", 5))
        .inOrder();
  }

  public void testAsMapReadsThrough() {
    Set<String> strings = Sets.newLinkedHashSet();
    Collections.addAll(strings, "one", "two", "three");
    Map<String, Integer> map = Maps.asMap(strings, LENGTH_FUNCTION);
    assertEquals(ImmutableMap.of("one", 3, "two", 3, "three", 5), map);

    assertThat(map.entrySet())
        .containsExactly(mapEntry("one", 3), mapEntry("two", 3), mapEntry("three", 5))
        .inOrder();
  }

  public void testAsMapReadsThrough() {
    Set<String> strings = Sets.newLinkedHashSet();
    Collections.addAll(strings, "one", "two", "three");
    Map<String, Integer> map = Maps.asMap(strings, LENGTH_FUNCTION);
    assertEquals(ImmutableMap.of("one", 3, "two", 3, "three", 5), map);

  /** All waiting threads. */
  @CheckForNull private volatile Waiter waiters;

  /** Constructor for use by subclasses. */
  protected AbstractFuture() {}

  // Gets and Timed Gets
  //
  // * Be responsive to interruption
  // * Don't create Waiter nodes if you aren't going to park, this helps reduce contention on the
  //   waiters field.

   *
   * <p>Note: the multimap assumes complete ownership over of {@code map} and the sets returned by
   * {@code factory}. Those objects should not be manually updated and they should not use soft,
   * weak, or phantom references.
   *
   * @param map place to store the mapping from each key to its corresponding values
   * @param factory supplier of new, empty sets that will each hold all values for a given key

   */
  interface InternalEntry<K, V, E extends InternalEntry<K, V, E>> {
    /** Gets the next entry in the chain. */
    E getNext();

    /** Gets the entry's hash. */
    int getHash();

    /** Gets the key for this entry. */
    K getKey();

    /** Gets the value for the entry. */
    V getValue();
  }

  /*

    assertThat(alreadyThere).containsExactly("already", "there", "freshly", "added");
    assertTrue(changed);
  }

  public void testAddAllToSet() {
    Set<String> alreadyThere = Sets.newLinkedHashSet(asList("already", "there"));
    List<String> oneMore = Lists.newArrayList("there");

    boolean changed = Iterators.addAll(alreadyThere, oneMore.iterator());

 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/guava/latest/com.github.benmanes.caffeine.guava/com/github/benmanes/caffeine/guava/CaffeinatedGuava.html">its
 * {@code CaffeinatedGuava} adapter class</a>, which lets you build a Guava {@code Cache} or a Guava
 * {@code LoadingCache} backed by a Guava {@code CacheLoader}.
 *
 * <p>Caffeine's API for asynchronous operations uses {@code CompletableFuture}: <a

      }
    }

    @Override
    public boolean equals(@CheckForNull Object o) {
      if (o == this) {
        return true;
      }
      synchronized (mutex) {
        return Sets.equalsImpl(delegate(), o);
      }
    }

    @Override
    public boolean remove(@CheckForNull Object o) {
      synchronized (mutex) {
        return Maps.removeEntryImpl(delegate(), o);
      }