* See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.graph;

import com.google.common.collect.ImmutableSet;
import java.util.AbstractSet;
import java.util.Set;
import org.jspecify.annotations.Nullable;

/**
 * Abstract base class for an incident edges set that allows different implementations of {@link

  }

  @Override
  public int count(@Nullable Object element) {
    return delegateMap.getOrDefault(element, 0);
  }

  @LazyInit private transient @Nullable ImmutableSet<E> elementSet;

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

  @Override
  Entry<E> getEntry(int index) {

      }
    }
  }

  ImmutableTable() {}

  @Override
  public ImmutableSet<Cell<R, C, V>> cellSet() {
    return (ImmutableSet<Cell<R, C, V>>) super.cellSet();
  }

  @Override
  abstract ImmutableSet<Cell<R, C, V>> createCellSet();

  @Override
  final UnmodifiableIterator<Cell<R, C, V>> cellIterator() {

import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class SingletonImmutableSet<E> extends ImmutableSet<E> {
  // We deliberately avoid caching the asList and hashCode here, to ensure that with

    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,

          // All collections are immutable empty. So safe for any type parameter.
          .put(Iterator.class, ImmutableSet.of().iterator())
          .put(PeekingIterator.class, peekingIterator(ImmutableSet.of().iterator()))
          .put(ListIterator.class, ImmutableList.of().listIterator())
          .put(Iterable.class, ImmutableSet.of())
          .put(Collection.class, ImmutableList.of())

   */
  @Override
  public abstract ImmutableSet<E> elementSet();

  @LazyInit private transient @Nullable ImmutableSet<Entry<E>> entrySet;

  @Override
  public ImmutableSet<Entry<E>> entrySet() {
    ImmutableSet<Entry<E>> es = entrySet;
    return (es == null) ? (entrySet = createEntrySet()) : es;
  }

  private ImmutableSet<Entry<E>> createEntrySet() {

    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());

      assertSame(thrownException, expected);
    }

    assertTrue(c1.isClosed());
    assertTrue(c2.isClosed());

    ImmutableSet<Throwable> suppressed = ImmutableSet.copyOf(thrownException.getSuppressed());
    assertEquals(2, suppressed.size());

    assertEquals(ImmutableSet.of(c1Exception, c2Exception), suppressed);
  }

  public void testNullCloseable() throws IOException {
    Closer closer = Closer.create();

  static final CharSink BROKEN_OPEN_SINK = new TestCharSink(OPEN_THROWS);

  private static final ImmutableSet<CharSource> BROKEN_SOURCES =
      ImmutableSet.of(BROKEN_CLOSE_SOURCE, BROKEN_OPEN_SOURCE, BROKEN_READ_SOURCE);
  private static final ImmutableSet<CharSink> BROKEN_SINKS =
      ImmutableSet.of(BROKEN_CLOSE_SINK, BROKEN_OPEN_SINK, BROKEN_WRITE_SINK);

  public void testCopyExceptions() {