}

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Collection<E> create(Object... elements) {
      return SerializableTester.reserialize(gen.create(elements));
    }

    @Override
    public E[] createArray(int length) {
      return gen.createArray(length);
    }

    @Override
    public Iterable<E> order(List<E> insertionOrder) {

 * can be used in the testers.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@NullMarked
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class MultimapKeySetTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  public void testKeySet() {
    for (Entry<K, V> entry : getSampleElements()) {
      assertTrue(multimap().keySet().contains(entry.getKey()));
    }
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testKeySetContainsNullKeyPresent() {

 * can be used in the testers.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@NullMarked
public class MinimalSet<E extends @Nullable Object> extends MinimalCollection<E> implements Set<E> {

  @SuppressWarnings("unchecked") // empty Object[] as E[]
  public static <E extends @Nullable Object> MinimalSet<E> of(E... contents) {
    return ofClassAndContents(Object.class, (E[]) new Object[0], asList(contents));

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

  // MultiplexingOutputStream).
  public HashingOutputStream(HashFunction hashFunction, OutputStream out) {
    super(checkNotNull(out));
    this.hasher = checkNotNull(hashFunction.newHasher());
  }

  @Override
  public void write(int b) throws IOException {
    hasher.putByte((byte) b);
    out.write(b);
  }

  @Override
  public void write(byte[] bytes, int off, int len) throws IOException {

 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *

        // noop
    }

    /**
     * Prints thread dump information to the logger at INFO level.
     */
    public static void printThreadDump() {
        processThreadDump(logger::info);
    }

    /**
     * Prints thread dump information to the logger at WARN level.
     */
    public static void printThreadDumpAsWarn() {
        processThreadDump(logger::warn);
    }

    /**

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class CollectionToStringTester<E> extends AbstractCollectionTester<E> {
  public void testToString_minimal() {
    assertNotNull("toString() should not return null", collection.toString());
  }

  @CollectionSize.Require(ZERO)
  @CollectionFeature.Require(absent = NON_STANDARD_TOSTRING)
  public void testToString_size0() {

 *
 * @author Nishant Thakkar
 * @since 10.0
 */
@GwtIncompatible
public class MockFutureListener implements Runnable {
  private final CountDownLatch countDownLatch;
  private final ListenableFuture<?> future;

  public MockFutureListener(ListenableFuture<?> future) {
    this.countDownLatch = new CountDownLatch(1);
    this.future = future;