* past them.)
     *
     * We could consider "lying" and omitting @CheckNotNull from all these fields. Normally, I'm not
     * a fan of that: What if we someday implement (presumably to be enabled during tests only)
     * bytecode rewriting that checks for any null value that passes through an API with a
     * known-non-null type? But that particular problem might not arise here, since we're not

     * Disables cycle detection. This option causes the factory to return unmodified lock
     * implementations provided by the JDK, and is provided to allow applications to easily
     * parameterize when cycle detection is enabled.
     *
     * <p>Note that locks created by a factory with this policy will not participate the
     * cycle detection performed by locks created by other factories.
     */
    DISABLED {
      @Override

/**
 * Static convenience methods that serve the same purpose as Java language <a
 * href="https://docs.oracle.com/javase/8/docs/technotes/guides/language/assert.html">assertions</a>,
 * except that they are always enabled. These methods should be used instead of Java assertions
 * whenever there is a chance the check may fail "in real life". Example:
 *
 * <pre>{@code
 * Bill bill = remoteService.getLastUnpaidBill();
 *

 * collection generator.
 *
 * <p>{@code GwtTestSuiteGenerator} expects every {@code DerivedIterator} implementation to provide
 * a one-arg constructor accepting its inner generator as an argument. This requirement enables it
 * to generate source code (since GWT cannot use reflection to generate the suites).
 *
 * @author Chris Povirk
 */
@GwtCompatible
public interface DerivedGenerator {
  TestSubjectGenerator<?> getInnerGenerator();

/**
 * Unit tests for {@link Callables}.
 *
 * @author Isaac Shum
 */
@GwtCompatible(emulated = true)
public class CallablesTest extends TestCase {

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testReturning() throws Exception {
    assertNull(Callables.returning(null).call());

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);

   *
   * @param key the non-null key whose value should be loaded
   * @return the value associated with {@code key}; <b>must not be null</b>
   * @throws Exception if unable to load the result
   * @throws InterruptedException if this method is interrupted. {@code InterruptedException} is
   *     treated like any other {@code Exception} in all respects except that, when it is caught,

 *   <dd>An extension of {@link java.util.Map} that guarantees the uniqueness of its values as well
 *       as that of its keys. This is sometimes called an "invertible map," since the restriction on
 *       values enables it to support an {@linkplain BiMap#inverse inverse view} -- which is another
 *       instance of {@code BiMap}.
 *   <dt>{@link Table}

        assertBitEquals(prev, aa.get(i));
        assertTrue(aa.compareAndSet(i, prev, x));
        assertBitEquals(x, aa.get(i));
        prev = x;
      }
    }
  }

  /** compareAndSet in one thread enables another waiting for value to succeed */
  public void testCompareAndSetInMultipleThreads() throws InterruptedException {
    final AtomicDoubleArray a = new AtomicDoubleArray(1);
    a.set(0, 1.0);
    Thread t =

#### Merging pull requests ####

Due to Guava's nature as a subset of Google's internal codebase which is
automatically synced to the public GitHub repository, we are unable to merge
pull requests directly into the master branch. Instead, once a pull request is
ready for merging, we'll make the appropriate changes in the internal codebase

    waiter.start();
    waiter.awaitWaiting();

    future.set(1);
    waiter.join();
  }

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testSetNull() throws Exception {
    future.set(null);
    assertSuccessful(future, null);
  }

  public void testSetExceptionNull() throws Exception {
    try {