assertFalse(
        "multiset.entrySet() contains a non-entry", getMultiset().entrySet().contains(e0()));
  }

  public void testEntrySet_twice() {
    assertEquals(
        "calling multiset.entrySet() twice returned unequal sets",
        getMultiset().entrySet(),
        getMultiset().entrySet());
  }

  @CollectionSize.Require(ZERO)
  public void testEntrySet_hashCode_size0() {

        return new ImmutableEnumSet<>(set);
    }
  }

  /*
   * Notes on EnumSet and <E extends Enum<E>>:
   *
   * This class isn't an arbitrary ForwardingImmutableSet because we need to
   * know that calling {@code clone()} during deserialization will return an
   * object that no one else has a reference to, allowing us to guarantee
   * immutability. Hence, we support only {@link EnumSet}.
   */

    if (digits == 0) {
      return new BigInteger(1, RANDOM_SOURCE);
    } else {
      return new BigInteger(digits, RANDOM_SOURCE).setBit(digits);
    }
  }

  /**
   * Equivalent to calling randomPositiveBigInteger(numBits) and then flipping the sign with 50%
   * probability.
   */
  static BigInteger randomNonZeroBigInteger(int numBits) {
    BigInteger result = randomPositiveBigInteger(numBits);

    node.thread = null; // mark as 'deleted'
    restart:
    while (true) {
      Waiter pred = null;
      Waiter curr = waiters;
      if (curr == Waiter.TOMBSTONE) {
        return; // give up if someone is calling complete
      }
      Waiter succ;
      while (curr != null) {
        succ = curr.next;
        if (curr.thread != null) { // we aren't unlinking this node, update pred.
          pred = curr;

  @CanIgnoreReturnValue
  @CheckForNull
  V forcePut(@ParametricNullness K key, @ParametricNullness V value);

  // Bulk Operations

  /**
   * {@inheritDoc}
   *
   * <p><b>Warning:</b> the results of calling this method may vary depending on the iteration order
   * of {@code map}.
   *
   * @throws IllegalArgumentException if an attempt to {@code put} any entry fails. Note that some

      }
      awaitUnchecked(barrier);
      assertThat(future.isDone()).isTrue();
      // inspect state and ensure it is correct!
      // asserts that all get calling threads received the same value
      Object result = Iterables.getOnlyElement(finalResults);
      if (result == CancellationException.class) {
        assertTrue(future.isCancelled());
        if (future.wasInterrupted()) {

    assertSame(e, urlFormParameterEscaper());
    assertBasicUrlEscaper(e);

    /*
     * Specified as safe by RFC 2396 but not by java.net.URLEncoder. These tests will start failing
     * when the escaper is made compliant with RFC 2396, but that's a good thing (just change them
     * to assertUnescaped).
     */
    assertEscaping(e, "%21", '!');
    assertEscaping(e, "%28", '(');

      this.className = checkNotNull(className);
    }

    /**
     * Configures the {@link ToStringHelper} so {@link #toString()} will ignore properties with null
     * value. The order of calling this method, relative to the {@code add()}/{@code addValue()}
     * methods, is not significant.
     *
     * @since 18.0 (since 12.0 as {@code Objects.ToStringHelper.omitNullValues()}).
     */

   * even to an intermediate buffer) should be considerably more efficient than potentially
   * copying the CharSequence to a String and then calling getBytes(Charset) on that String, in
   * reality there are optimizations that make the getBytes(Charset) approach considerably faster,
   * at least for commonly used charsets like UTF-8.
   */

  @Override

 *   <li>a {@linkplain ThreadFactory#newThread backing thread factory}
 * </ul>
 *
 * <p>If no backing thread factory is provided, a default backing thread factory is used as if by
 * calling {@code setThreadFactory(}{@link Executors#defaultThreadFactory()}{@code )}.
 *
 * @author Kurt Alfred Kluever
 * @since 4.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault