}

  abstract ImmutableSet<Entry<K, V>> createEntrySet();

  @LazyInit @RetainedWith @CheckForNull private transient ImmutableSet<K> keySet;

  /**
   * Returns an immutable set of the keys in this map, in the same order that they appear in {@link
   * #entrySet}.
   */
  @Override
  public ImmutableSet<K> keySet() {
    ImmutableSet<K> result = keySet;

    ExceptionType(Class<? extends Exception> exceptionType) {
      this.exceptionType = exceptionType;
    }
  }

  private static final ImmutableSet<Class<? extends Exception>> OTHER_EXCEPTION_TYPES =
      ImmutableSet.of(
          BackingStoreException.class,
          BrokenBarrierException.class,
          CloneNotSupportedException.class,
          DataFormatException.class,

    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 =

    }
  }

  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(

    }
  }

  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(

          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<?>>>

    builder.putAll("bar", Arrays.asList(4, 5));
    builder.putAll("foo", Arrays.asList(6, 7));
    Multimap<String, Integer> multimap = builder.build();
    assertEquals(ImmutableSet.of(1, 2, 3, 6, 7), multimap.get("foo"));
    assertEquals(ImmutableSet.of(4, 5), multimap.get("bar"));
    assertEquals(7, multimap.size());
  }

  public void testBuilderPutAllVarargs() {

  @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

  private static final QuantilesAlgorithm REFERENCE_ALGORITHM = QuantilesAlgorithm.SORTING;
  private static final Set<QuantilesAlgorithm> NON_REFERENCE_ALGORITHMS =
      Sets.difference(
          ImmutableSet.copyOf(QuantilesAlgorithm.values()), ImmutableSet.of(REFERENCE_ALGORITHM));

  private double[] dataset;

  @Override
  protected void setUp() {
    dataset = new double[DATASET_SIZE];
    for (int i = 0; i < DATASET_SIZE; i++) {

    return MoreObjects.firstNonNull(subscribers.get(eventType), ImmutableSet.<Subscriber>of());
  }

  /**
   * Gets an iterator representing an immutable snapshot of all subscribers to the given event at
   * the time this method is called.
   */
  Iterator<Subscriber> getSubscribers(Object event) {
    ImmutableSet<Class<?>> eventTypes = flattenHierarchy(event.getClass());