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(

  // the CacheBuilder default).
  private Set<Integer> concurrencyLevels = Sets.newHashSet((Integer) null);
  private Set<Integer> initialCapacities = Sets.newHashSet((Integer) null);
  private Set<Integer> maximumSizes = Sets.newHashSet((Integer) null);
  private Set<DurationSpec> expireAfterWrites = Sets.newHashSet((DurationSpec) null);
  private Set<DurationSpec> expireAfterAccesses = Sets.newHashSet((DurationSpec) null);

    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>>() {

import com.google.common.collect.testing.SampleElements.Enums;
import java.util.Collections;
import java.util.List;
import java.util.Set;

/**
 * An abstract TestSetGenerator for generating sets containing enum values.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TestEnumSetGenerator implements TestSetGenerator<AnEnum> {
  @Override

  @Override
  public void setUp() {
    friends = Sets.newHashSet("Tom", "Joe", "Dave");
    enemies = Sets.newHashSet("Dick", "Harry", "Tom");
  }

  public void testUnion() {
    Set<String> all = Sets.union(friends, enemies);
    assertEquals(5, all.size());

    ImmutableSet<String> immut = Sets.union(friends, enemies).immutableCopy();
    HashSet<String> mut = Sets.union(friends, enemies).copyInto(new HashSet<String>());