@GwtIncompatible // Predicates.instanceOf
  public void testIsInstanceOf_interface() {
    Predicate<@Nullable Object> isComparable = Predicates.instanceOf(Comparable.class);

    assertTrue(isComparable.apply(1));
    assertTrue(isComparable.apply(2.0f));
    assertTrue(isComparable.apply(""));
    assertFalse(isComparable.apply(null));
  }

  @GwtIncompatible // Predicates.instanceOf
  public void testIsInstanceOf_equality() {

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of() {
    return ImmutableSortedSet.of();
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of(E e) {
    return ImmutableSortedSet.of(e);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of(E e1, E e2) {
    return ImmutableSortedSet.of(e1, e2);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of() {
    return ImmutableSortedSet.of();
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of(E e) {
    return ImmutableSortedSet.of(e);
  }

  @Override
  protected <E extends Comparable<? super E>> SortedSet<E> of(E e1, E e2) {
    return ImmutableSortedSet.of(e1, e2);
  }

   */
  public static <E extends Comparable<E>> MinMaxPriorityQueue<E> create() {
    return new Builder<Comparable<E>>(Ordering.natural()).create();
  }

  /**
   * Creates a new min-max priority queue using natural order, no maximum size, and initially
   * containing the given elements.
   */
  public static <E extends Comparable<E>> MinMaxPriorityQueue<E> create(

  @Override
  @SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??
  public int compare(Comparable<?> left, Comparable<?> right) {
    checkNotNull(left); // for GWT
    checkNotNull(right);
    return ((Comparable<Object>) left).compareTo(right);
  }

  @Override
  @SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??

   */
  public static <E extends Comparable<E>> MinMaxPriorityQueue<E> create() {
    return new Builder<Comparable<E>>(Ordering.natural()).create();
  }

  /**
   * Creates a new min-max priority queue using natural order, no maximum size, and initially
   * containing the given elements.
   */
  public static <E extends Comparable<E>> MinMaxPriorityQueue<E> create(

  @Override
  @SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??
  public int compare(Comparable<?> left, Comparable<?> right) {
    checkNotNull(left); // for GWT
    checkNotNull(right);
    return ((Comparable<Object>) left).compareTo(right);
  }

  @Override
  @SuppressWarnings("unchecked") // TODO(kevinb): the right way to explain this??

    assertEquals(
        "Comparable fixture must be thirdobject delivered.", compEvent, objectEvents.get(2));

    // Check the Catcher<Comparable<?>>...
    assertEquals("Two Comparable<?>s should be delivered.", 2, compEvents.size());
    assertEquals("String fixture must be first comparable delivered.", EVENT, compEvents.get(0));
    assertEquals(

    assertEquals(
        "Comparable fixture must be thirdobject delivered.", compEvent, objectEvents.get(2));

    // Check the Catcher<Comparable<?>>...
    assertEquals("Two Comparable<?>s should be delivered.", 2, compEvents.size());
    assertEquals("String fixture must be first comparable delivered.", EVENT, compEvents.get(0));
    assertEquals(

    return suite;
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of() {
    return ImmutableSet.of();
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of(E e) {
    return ImmutableSet.of(e);
  }

  @Override
  protected <E extends Comparable<? super E>> Set<E> of(E e1, E e2) {
    return ImmutableSet.of(e1, e2);
  }

  @Override