public void testReturning() throws Exception {
    assertNull(Callables.returning(null).call());

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);
    assertSame(value, callable.call());
    // Expect the same value on subsequent calls
    assertSame(value, callable.call());
  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testAsAsyncCallable() throws Exception {

   * target} object, enforcing the specified time limit on each call. This time-limited delegation
   * is also performed for calls to {@link Object#equals}, {@link Object#hashCode}, and {@link
   * Object#toString}.
   *
   * <p>If the target method call finishes before the limit is reached, the return value or

     *
     * 1. The client thread begins to block on a get() call to a future.
     * 2. The client thread is interrupted sometime before the result would be
     *   available.
     * 3. We expect the client's get() to throw an InterruptedException.
     * 4. We expect the client thread's interrupt state to be false.
     * 5. The client thread again makes a blocking call to get().
     * 6. Now the result becomes available.

   * value. Otherwise, a call that passes one {@code loader} may return the result of another call
   * with a differently behaving {@code loader}. For example, a call that requests a short timeout
   * for an RPC may wait for a similar call that requests a long timeout, or a call by an
   * unprivileged user may return a resource accessible only to a privileged user making a similar

      throw new AssertionFailedError();
    }

    @Override
    public V get() throws InterruptedException {
      /*
       * Wait a little to give us time to call addListener before the future's
       * value is set in addition to the call we'll make after then.
       */
      allowGetToComplete.await(1, SECONDS);
      throw new RuntimeException("expected, should be caught");
    }

    @Override

    final Exception e = new Exception();
    TrustedListenableFutureTask<Integer> task =
        TrustedListenableFutureTask.create(
            new Callable<Integer>() {
              @Override
              public Integer call() throws Exception {
                throw e;
              }
            });
    task.run();
    assertTrue(task.isDone());
    assertFalse(task.isCancelled());
    try {
      getDone(task);
      fail();

        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testMappedToNull() {

   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *
   * <p>Caches loaded by a {@link CacheLoader} will call {@link CacheLoader#load} to load new values

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

/**
 * A {@link ListenableFuture} whose result can be set by a {@link #set(Object)}, {@link
 * #setException(Throwable)} or {@link #setFuture(ListenableFuture)} call. It can also, like any
 * other {@code Future}, be {@linkplain #cancel cancelled}.
 *
 * <p>{@code SettableFuture} is the recommended {@code ListenableFuture} implementation when your

public class ListenerCallQueueTest extends TestCase {

  private static final ListenerCallQueue.Event<Object> THROWING_EVENT =
      new ListenerCallQueue.Event<Object>() {
        @Override
        public void call(Object object) {
          throw new RuntimeException();
        }

        @Override
        public String toString() {
          return "throwing()";
        }
      };