Iterators.removeIf(
            list.iterator(),
            new Predicate<String>() {
              @Override
              public boolean apply(String s) {
                return s.equals("b") || s.equals("d") || s.equals("f");
              }
            }));
    assertEquals(newArrayList("a", "c", "e"), list);
    assertFalse(
        Iterators.removeIf(
            list.iterator(),

    @Override
    Set<E> delegate() {
      return (Set<E>) super.delegate();
    }

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

    @Override
    public int hashCode() {
      synchronized (mutex) {
        return delegate().hashCode();

 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 2.0 (implements {@code NavigableMap} since 12.0)
 */

      }
      return false;
    }

    @Override
    public boolean equals(@CheckForNull Object obj) {
      if (obj instanceof PowerSet) {
        PowerSet<?> that = (PowerSet<?>) obj;
        return inputSet.keySet().equals(that.inputSet.keySet());
      }
      return super.equals(obj);
    }

    @Override
    public int hashCode() {
      /*

   * #newListMultimap}, {@link #newSetMultimap} or {@link #newSortedSetMultimap} instead, to avoid
   * very surprising behavior from {@link Multimap#equals}.
   *
   * <p>The {@code factory}-generated and {@code map} classes determine the multimap iteration
   * order. They also specify the behavior of the {@code equals}, {@code hashCode}, and {@code
   * toString} methods for the multimap and its returned views. However, the multimap's {@code get}

 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *
 * @author Jared Levy
 * @author Louis Wasserman
 * @since 2.0 (implements {@code NavigableMap} since 12.0)
 */

        Iterators.removeIf(
            list.iterator(),
            new Predicate<String>() {
              @Override
              public boolean apply(String s) {
                return s.equals("b") || s.equals("d") || s.equals("f");
              }
            }));
    assertEquals(newArrayList("a", "c", "e"), list);
    assertFalse(
        Iterators.removeIf(
            list.iterator(),

    assertTrue(actual.contains(list(2, 3)));
    assertTrue(actual.contains(list(2, 4)));
    assertFalse(actual.contains(list(3, 1)));
  }

  public void testCartesianProduct_equals() {
    Set<List<Integer>> cartesian = Sets.cartesianProduct(set(1, 2), set(3, 4));
    ImmutableSet<List<Integer>> equivalent =
        ImmutableSet.of(ImmutableList.of(1, 3), ImmutableList.of(1, 4), list(2, 3), list(2, 4));

    assertSame(unmod, unmod.inverse().inverse());

    /* Unmodifiable is a view. */
    mod.put(4, "four");
    assertEquals(true, unmod.get(4).equals("four"));
    assertEquals(true, unmod.inverse().get("four").equals(4));

    /* UnsupportedOperationException on direct modifications. */
    try {
      unmod.put(4, "four");
      fail("UnsupportedOperationException expected");

    assertSame(unmod, unmod.inverse().inverse());

    /* Unmodifiable is a view. */
    mod.put(4, "four");
    assertEquals(true, unmod.get(4).equals("four"));
    assertEquals(true, unmod.inverse().get("four").equals(4));

    /* UnsupportedOperationException on direct modifications. */
    try {
      unmod.put(4, "four");
      fail("UnsupportedOperationException expected");