}

  public void testCreate_empty() {
    assertEquals(ImmutableSet.of(), ContiguousSet.create(Range.closedOpen(1, 1), integers()));
    assertEquals(ImmutableSet.of(), ContiguousSet.closedOpen(1, 1));
    assertEquals(ImmutableSet.of(), ContiguousSet.create(Range.openClosed(5, 5), integers()));
    assertEquals(
        ImmutableSet.of(), ContiguousSet.create(Range.lessThan(Integer.MIN_VALUE), integers()));
    assertEquals(

  static final ImmutableTable<Object, Object, Object> EMPTY =
      new SparseImmutableTable<>(
          ImmutableList.<Cell<Object, Object, Object>>of(), ImmutableSet.of(), ImmutableSet.of());

  private final ImmutableMap<R, ImmutableMap<C, V>> rowMap;
  private final ImmutableMap<C, ImmutableMap<R, V>> columnMap;

    assertThat(undirectedGraph.edges()).isEmpty();
    assertThat(undirectedGraph.addEdge(N1, N2, E12)).isTrue();
    assertThat(undirectedGraph.edgesConnecting(N1, N2)).isEqualTo(ImmutableSet.of(E12));
    assertThat(undirectedGraph.edgesConnecting(N2, N1)).isEqualTo(ImmutableSet.of(E12));

    // By default, parallel edges are not allowed.
    IllegalArgumentException e =

    if (result == null) {
      return null;
    } else {
      return (V) result;
    }
  }

  @Override
  ImmutableSet<Entry<K, V>> createEntrySet() {
    return new RegularImmutableMap.EntrySet<K, V>(this, alternatingKeysAndValues, keyOffset, size);
  }

  @Override
  ImmutableSet<K> createKeySet() {
    @SuppressWarnings("unchecked")
    ImmutableList<K> keyList =
        (ImmutableList<K>)

  @Override
  public int count(@CheckForNull Object element) {
    return contents.get(element);
  }

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

  @Override
  public ImmutableSet<E> elementSet() {
    ImmutableSet<E> result = elementSet;
    return (result == null) ? elementSet = new ElementSet() : result;
  }

  @WeakOuter
  private final class ElementSet extends IndexedImmutableSet<E> {

    @Override

          return key.toString();
        }
      };

  private CacheBuilderFactory factoryWithAllKeyStrengths() {
    return new CacheBuilderFactory()
        .withKeyStrengths(ImmutableSet.of(STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.of(STRONG, Strength.WEAK, Strength.SOFT));
  }

  private Iterable<LoadingCache<Key, String>> caches() {
    CacheBuilderFactory factory = factoryWithAllKeyStrengths();

          ImmutableList.Builder::combine,
          ImmutableList.Builder::build);

  private static final Collector<Object, ?, ImmutableSet<Object>> TO_IMMUTABLE_SET =
      Collector.of(
          ImmutableSet::builder,
          ImmutableSet.Builder::add,
          ImmutableSet.Builder::combine,
          ImmutableSet.Builder::build);

  @GwtIncompatible
  private static final Collector<Range<Comparable<?>>, ?, ImmutableRangeSet<Comparable<?>>>

  /**
   * RegularImmutableAsList should assume its input is null-free without checking, because it only
   * gets invoked from other immutable collections.
   */
  public void testDoesntCheckForNull() {
    ImmutableSet<Integer> set = ImmutableSet.of(1, 2, 3);
    ImmutableList<Integer> unused =
        new RegularImmutableAsList<Integer>(set, new @Nullable Object[] {null, null, null});
    // shouldn't throw!
  }

        .withKeyStrengths(ImmutableSet.of(Strength.STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.copyOf(Strength.values()))
        .withConcurrencyLevels(ImmutableSet.of(1, 4, 16, 64))
        .withMaximumSizes(ImmutableSet.of(0, 1, 10, 100, 1000))
        .withInitialCapacities(ImmutableSet.of(0, 1, 10, 100, 1000))
        .withExpireAfterWrites(
            ImmutableSet.of(

        .withKeyStrengths(ImmutableSet.of(Strength.STRONG, Strength.WEAK))
        .withValueStrengths(ImmutableSet.copyOf(Strength.values()))
        .withConcurrencyLevels(ImmutableSet.of(1, 4, 16, 64))
        .withMaximumSizes(ImmutableSet.of(0, 1, 10, 100, 1000))
        .withInitialCapacities(ImmutableSet.of(0, 1, 10, 100, 1000))
        .withExpireAfterWrites(
            ImmutableSet.of(