*
 * @author Gregory Kick
 * @since 10.0
 */
@GwtCompatible
@SuppressWarnings("rawtypes") // allow ungenerified Comparable types
public abstract class ContiguousSet<C extends Comparable> extends ImmutableSortedSet<C> {
  /**
   * Returns a {@code ContiguousSet} containing the same values in the given domain {@linkplain
   * Range#contains contained} by the range.
   *

  }

  /**
   * Returns an {@code ImmutableSortedSet} containing all of the elements from this {@code
   * FluentIterable} in the order specified by {@code comparator}, with duplicates (determined by
   * {@code comparator.compare(x, y) == 0}) removed. To produce an {@code ImmutableSortedSet} sorted
   * by its natural ordering, use {@code toSortedSet(Ordering.natural())}.
   *

    }
  }

  private transient @Nullable ImmutableSortedSet<K> keySet;

  @Override
  public ImmutableSortedSet<K> keySet() {
    ImmutableSortedSet<K> ks = keySet;
    return (ks == null) ? (keySet = createKeySet()) : ks;
  }

  @Override
  ImmutableSortedSet<K> createKeySet() {
    // the keySet() of the delegate is only a Set and TreeMap.navigatableKeySet

 *
 * @author Gregory Kick
 * @since 10.0
 */
@GwtCompatible
@SuppressWarnings("rawtypes") // allow ungenerified Comparable types
public abstract class ContiguousSet<C extends Comparable> extends ImmutableSortedSet<C> {
  /**
   * Returns a {@code ContiguousSet} containing the same values in the given domain {@linkplain
   * Range#contains contained} by the range.
   *

    assertEquals(ImmutableSet.of(), ArbitraryInstances.get(ImmutableSet.class));
    assertEquals(ImmutableSortedSet.of(), ArbitraryInstances.get(SortedSet.class));
    assertEquals(ImmutableSortedSet.of(), ArbitraryInstances.get(ImmutableSortedSet.class));
    assertEquals(ImmutableList.of(), ArbitraryInstances.get(Collection.class));

          .put(ImmutableList.class, ImmutableList.of())
          .put(Set.class, ImmutableSet.of())
          .put(ImmutableSet.class, ImmutableSet.of())
          .put(SortedSet.class, ImmutableSortedSet.of())
          .put(ImmutableSortedSet.class, ImmutableSortedSet.of())
          .put(NavigableSet.class, Sets.unmodifiableNavigableSet(Sets.newTreeSet()))
          .put(Map.class, ImmutableMap.of())
          .put(ImmutableMap.class, ImmutableMap.of())

    assertEquals(ImmutableSet.of(), ArbitraryInstances.get(ImmutableSet.class));
    assertEquals(ImmutableSortedSet.of(), ArbitraryInstances.get(SortedSet.class));
    assertEquals(ImmutableSortedSet.of(), ArbitraryInstances.get(ImmutableSortedSet.class));
    assertEquals(ImmutableList.of(), ArbitraryInstances.get(Collection.class));

  }

  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();
  }

    assertFreshInstance(new TypeToken<ImmutableSet<String>>() {});
  }

  public void testImmutableSortedSet() {
    assertFreshInstance(new TypeToken<ImmutableSortedSet<String>>() {});
  }

  public void testImmutableMultiset() {
    assertFreshInstance(new TypeToken<ImmutableSortedSet<String>>() {});
    assertNotInstantiable(new TypeToken<ImmutableMultiset<EmptyEnum>>() {});
  }

  public void testImmutableCollection() {

    // path, so we test that separately
    assertTrue(range.containsAll(ImmutableSortedSet.of(3, 3, 4, 5)));
    assertTrue(range.containsAll(ImmutableSortedSet.of(3)));
    assertTrue(range.containsAll(ImmutableSortedSet.<Integer>of()));
    assertFalse(range.containsAll(ImmutableSortedSet.of(3, 3, 4, 5, 6)));

    assertTrue(Range.openClosed(3, 3).containsAll(Collections.<Integer>emptySet()));
  }