"containsAll(sameElements) should return true",
        collection.containsAll(MinimalCollection.of(createSamplesArray())));
  }

  @SuppressWarnings("ModifyingCollectionWithItself")
  public void testContainsAll_self() {
    assertTrue("containsAll(this) should return true", collection.containsAll(collection));
  }

  public void testContainsAll_partialOverlap() {
    assertFalse(

        "containsAll(sameElements) should return true",
        collection.containsAll(MinimalCollection.of(createSamplesArray())));
  }

  @SuppressWarnings("ModifyingCollectionWithItself")
  public void testContainsAll_self() {
    assertTrue("containsAll(this) should return true", collection.containsAll(collection));
  }

  public void testContainsAll_partialOverlap() {
    assertFalse(

    public boolean add(E element) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.add(element);
    }

    @Override
    public boolean containsAll(Collection<?> collection) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsAll(collection);
    }

    @Override
    public boolean addAll(Collection<? extends E> collection) {
      assertTrue(Thread.holdsLock(mutex));

    }
    if (!SortedIterables.hasSameComparator(comparator(), targets) || (targets.size() <= 1)) {
      return super.containsAll(targets);
    }

    /*
     * If targets is a sorted set with the same comparator, containsAll can run
     * in O(n) time stepping through the two collections.
     */
    Iterator<E> thisIterator = iterator();

  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> targets) {
    return delegate.containsAll(targets);
  }

  @Override
  public int size() {
    return delegate.size();
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

    Range<Integer> range = Range.closed(3, 5);
    assertTrue(range.containsAll(asList(3, 3, 4, 5)));
    assertFalse(range.containsAll(asList(3, 3, 4, 5, 6)));

    // We happen to know that natural-order sorted sets use a different code
    // path, so we test that separately
    assertTrue(range.containsAll(ImmutableSortedSet.of(3, 3, 4, 5)));
    assertTrue(range.containsAll(ImmutableSortedSet.of(3)));

    return Arrays.asList(contents).contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> collection) {
    if (!allowNulls) {
      for (Object object : collection) {
        // behave badly
        if (object == null) {
          throw new NullPointerException();
        }
      }
    }
    return super.containsAll(collection);
  }

  @Override
  public Iterator<E> iterator() {

    SortedSet<String> set = of("a", "b", "f");
    assertTrue(set.containsAll(Collections.emptyList()));
    assertTrue(set.containsAll(asList("b")));
    assertTrue(set.containsAll(asList("b", "b")));
    assertTrue(set.containsAll(asList("b", "f")));
    assertTrue(set.containsAll(asList("b", "f", "a")));
    assertFalse(set.containsAll(asList("d")));
    assertFalse(set.containsAll(asList("z")));
    assertFalse(set.containsAll(asList("b", "d")));

    return delegate.contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> collection) {
    if (collection instanceof ImmutableEnumSet<?>) {
      collection = ((ImmutableEnumSet<?>) collection).delegate;
    }
    return delegate.containsAll(collection);
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

    return comparator;
  }

  @Override
  public boolean contains(Object object) {
    return delegate.contains(checkValid(object));
  }

  @Override
  public boolean containsAll(Collection<?> c) {
    return delegate.containsAll(c);
  }

  @Override
  public Iterator<E> descendingIterator() {
    return delegate.descendingIterator();
  }

  @Override
  public NavigableSet<E> descendingSet() {