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(

    Set<String> set = of("a", "b");
    assertEquals(Sets.newHashSet("a", "b"), set);
  }

  public void testCreation_threeElements() {
    Set<String> set = of("a", "b", "c");
    assertEquals(Sets.newHashSet("a", "b", "c"), set);
  }

  public void testCreation_fourElements() {
    Set<String> set = of("a", "b", "c", "d");
    assertEquals(Sets.newHashSet("a", "b", "c", "d"), set);
  }

    Set<String> set = of("a", "b");
    assertEquals(Sets.newHashSet("a", "b"), set);
  }

  public void testCreation_threeElements() {
    Set<String> set = of("a", "b", "c");
    assertEquals(Sets.newHashSet("a", "b", "c"), set);
  }

  public void testCreation_fourElements() {
    Set<String> set = of("a", "b", "c", "d");
    assertEquals(Sets.newHashSet("a", "b", "c", "d"), set);
  }

    assertEquals("google", keySet.last());
    assertEquals(StringLength.COMPARATOR, keySet.comparator());
    assertEquals(Sets.<@Nullable String>newHashSet(null, "tree"), keySet.headSet("yahoo"));
    assertEquals(Sets.newHashSet("google"), keySet.tailSet("yahoo"));
    assertEquals(Sets.newHashSet("tree"), keySet.subSet("ask", "yahoo"));
  }

  @GwtIncompatible // SerializableTester

  @Beta // TODO: b/288085449 - Remove @Beta after we're sure that Java 8 APIs are safe for Android
  public FakeTicker advance(Duration duration) {
    return advance(duration.toNanos());
  }

  /**
   * Sets the increment applied to the ticker whenever it is queried.
   *
   * <p>The default behavior is to auto increment by zero. i.e: The ticker is left unchanged when
   * queried.
   */

    }

    @Override
    Set<E> createElementSet() {
      return Sets.filter(unfiltered.elementSet(), predicate);
    }

    @Override
    Iterator<E> elementIterator() {
      throw new AssertionError("should never be called");
    }

    @Override
    Set<Entry<E>> createEntrySet() {
      return Sets.filter(
          unfiltered.entrySet(),
          new Predicate<Entry<E>>() {

   * of their natural ordering.
   */
  public static <E extends Comparable<?>> Builder<E> reverseOrder() {
    return new Builder<>(Collections.reverseOrder());
  }

  /**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by their

    testers.add(SetCreationTester.class);
    testers.add(SetHashCodeTester.class);
    testers.add(SetEqualsTester.class);
    testers.add(SetRemoveTester.class);
    // SetRemoveAllTester doesn't exist because, Sets not permitting
    // duplicate elements, there are no tests for Set.removeAll() that aren't
    // covered by CollectionRemoveAllTester.
    return testers;
  }

  @Override

  public void testEntrySet() {
    Multiset<Color> ms = EnumMultiset.create(Color.class);
    ms.add(Color.BLUE, 3);
    ms.add(Color.YELLOW, 1);
    ms.add(Color.RED, 2);

    Set<Object> uniqueEntries = Sets.newIdentityHashSet();
    uniqueEntries.addAll(ms.entrySet());
    assertEquals(3, uniqueEntries.size());
  }

  // Wrapper of EnumMultiset factory methods, because we need to skip create(Class).