.testForwarding(
            SortedSet.class,
            new Function<SortedSet, SortedSet>() {
              @Override
              public SortedSet apply(SortedSet delegate) {
                return wrap(delegate);
              }
            });
  }

  public void testEquals() {
    SortedSet<String> set1 = ImmutableSortedSet.of("one");
    SortedSet<String> set2 = ImmutableSortedSet.of("two");

        .testForwarding(
            SortedSet.class,
            new Function<SortedSet, SortedSet>() {
              @Override
              public SortedSet apply(SortedSet delegate) {
                return wrap(delegate);
              }
            });
  }

  public void testEquals() {
    SortedSet<String> set1 = ImmutableSortedSet.of("one");
    SortedSet<String> set2 = ImmutableSortedSet.of("two");

    for (Collection<V> valueCollection : multimap().asMap().values()) {
      SortedSet<V> valueSet = (SortedSet<V>) valueCollection;
      assertEquals(multimap().valueComparator(), valueSet.comparator());
    }
  }

  public void testAsMapGetImplementsSortedSet() {
    for (K key : multimap().keySet()) {
      SortedSet<V> valueSet = (SortedSet<V>) multimap().asMap().get(key);

    }

    @Override
    public SortedSet<E> subSet(E fromElement, E toElement) {
      return subSet(fromElement, true, toElement, false);
    }

    @Override
    public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().tailSet(fromElement, inclusive);
    }

    @Override
    public SortedSet<E> tailSet(E fromElement) {

    }

    @Override
    public SortedSet<E> subSet(E fromElement, E toElement) {
      return subSet(fromElement, true, toElement, false);
    }

    @Override
    public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().tailSet(fromElement, inclusive);
    }

    @Override
    public SortedSet<E> tailSet(E fromElement) {

        delegate.subSet(
            checkValid(fromElement), fromInclusive, checkValid(toElement), toInclusive));
  }

  @Override
  public SortedSet<E> subSet(E fromElement, E toElement) {
    return subSet(fromElement, true, toElement, false);
  }

  @Override
  public SortedSet<E> tailSet(E fromElement) {
    return tailSet(fromElement, true);
  }

  @Override

  }

  public void testFirst_sortedSet() {
    SortedSet<String> sortedSet = ImmutableSortedSet.of("b", "c", "a");
    assertThat(FluentIterable.from(sortedSet).first()).hasValue("a");
  }

  public void testFirst_emptySortedSet() {
    SortedSet<String> sortedSet = ImmutableSortedSet.of();
    assertThat(FluentIterable.from(sortedSet).first()).isAbsent();
  }

        TestSortedSetGenerator<E> delegate, Bound to, Bound from) {
      super(delegate, to, from);
    }

    @Override
    NavigableSet<E> createSubSet(SortedSet<E> sortedSet, E firstExclusive, E lastExclusive) {
      NavigableSet<E> set = (NavigableSet<E>) sortedSet;
      if (from == Bound.NO_BOUND && to == Bound.INCLUSIVE) {
        return set.headSet(lastInclusive, true);

        TestSortedSetGenerator<E> delegate, Bound to, Bound from) {
      super(delegate, to, from);
    }

    @Override
    NavigableSet<E> createSubSet(SortedSet<E> sortedSet, E firstExclusive, E lastExclusive) {
      NavigableSet<E> set = (NavigableSet<E>) sortedSet;
      if (from == Bound.NO_BOUND && to == Bound.INCLUSIVE) {
        return set.headSet(lastInclusive, true);

      return new SortedAsMap(sortedMap().tailMap(fromKey));
    }

    @CheckForNull SortedSet<K> sortedKeySet;

    // returns a SortedSet, even though returning a Set would be sufficient to
    // satisfy the SortedMap.keySet() interface
    @Override
    public SortedSet<K> keySet() {
      SortedSet<K> result = sortedKeySet;
      return (result == null) ? sortedKeySet = createKeySet() : result;
    }