* Futures#addCallback addCallback()}.
   *
   * <p>Memory consistency effects: Actions in a thread prior to adding a listener <a
   * href="https://docs.oracle.com/javase/specs/jls/se7/html/jls-17.html#jls-17.4.5">
   * <i>happen-before</i></a> its execution begins, perhaps in another thread.
   *
   * <p>Guava implementations of {@code ListenableFuture} promptly release references to listeners

    val relay = edit(file, pipe.source, metadata, 5)
    val future1 = executor.submit(sourceReader(relay.newSource()))
    val future2 = executor.submit(sourceReader(relay.newSource()))
    Thread.sleep(500)
    sink.writeUtf8("abcdefghij")
    Thread.sleep(500)
    sink.writeUtf8("klmnopqrst")
    sink.close()
    assertThat<ByteString>(future1.get())
      .isEqualTo("abcdefghijklmnopqrst".encodeUtf8())

 * method.
 *
 * <p>The {@code standard} methods and any collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Louis Wasserman
 */
@ElementTypesAreNonnullByDefault
public abstract class ForwardingSortedMultiset<E extends @Nullable Object>

                                            <thead>
                                            <tr>
                                                <th><la:message key="labels.user_list_name"/></th>
                                            </tr>
                                            </thead>
                                            <tbody>

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An Iterator implementation which draws elements from a queue, removing them from the queue as it
 * iterates. This class is not thread safe.
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
final class ConsumingQueueIterator<T extends @Nullable Object> extends AbstractIterator<T> {
  private final Queue<T> queue;

import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import javax.annotation.CheckForNull;

/**
 * Soft reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible

    CountDownLatch doneSignal = new CountDownLatch(1);
    Thread thread =
        new Thread(
            () -> {
              try {
                cache.get(key, loader);
              } catch (UncheckedExecutionException | ExecutionException e) {
                doneSignal.countDown();
              }
            });
    thread.start();

    boolean done = doneSignal.await(1, SECONDS);

    CountDownLatch doneSignal = new CountDownLatch(1);
    Thread thread =
        new Thread(
            () -> {
              try {
                cache.get(key, loader);
              } catch (UncheckedExecutionException | ExecutionException e) {
                doneSignal.countDown();
              }
            });
    thread.start();

    boolean done = doneSignal.await(1, SECONDS);

        def content = parse('''<section>
                <section><title>Properties</title>
                    <table><thead><tr><td/></tr></thead></table>
                </section>
                <section><title>Methods</title>
                    <table><thead><tr><td/></tr></thead></table>
                </section>
            </section>
        ''')

        when:
        ClassDoc doc = withCategories {

 *       appropriate factory method for details. View collections such as {@link
 *       ImmutableMultiset#elementSet} iterate in the same order as the parent, except as noted.
 *   <li><b>Thread safety.</b> It is safe to access this collection concurrently from multiple
 *       threads.
 *   <li><b>Integrity.</b> This type cannot be subclassed outside this package (which would allow
 *       these guarantees to be violated).
 * </ul>
 *