if (isSatisfied(guard)) {
        guard.condition.signal();
        break;
      }
    }
  }

  /**
   * Exactly like signalNextWaiter, but caller guarantees that guardToSkip need not be considered,
   * because caller has previously checked that guardToSkip.isSatisfied() returned false. An
   * optimization for the case that guardToSkip.isSatisfied() may be expensive.
   *

    @SuppressWarnings("unused") // Called by reflection
    private void privateMethod() {}

    @SuppressWarnings("unused") // Called by reflection
    void packagePrivateMethod() {}

    @SuppressWarnings("unused") // Called by reflection
    protected void protectedMethod() {}

    @SuppressWarnings("unused") // Called by reflection
    public void publicMethod() {}
  }

   * exception is propagated to the caller exactly as-is. If, on the other hand, the time limit is
   * reached, the proxy will attempt to abort the call to the target, and will throw an {@link
   * UncheckedTimeoutException} to the caller.
   *
   * <p>It is important to note that the primary purpose of the proxy object is to return control to

        new FutureCallback<String>() {
          private boolean called = false;

          @Override
          public void onSuccess(String result) {
            fail("Was not expecting onSuccess() to be called.");
          }

          @Override
          public synchronized void onFailure(Throwable t) {
            assertFalse(called);
            assertThat(t).isInstanceOf(CancellationException.class);

   * be thread-safe.
   *
   * @since 13.0
   */
  public interface Policy {

    /**
     * Called when a potential deadlock is encountered. Implementations can throw the given {@code
     * exception} and/or execute other desired logic.
     *
     * <p>Note that the method will be called even upon an invocation of {@code tryLock()}. Although

    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Finish the task by unblocking the task latch.  Then wait for the
    // listener to be called by blocking on the listener latch.
    taskLatch.countDown();
    assertEquals(25, task.get().intValue());
    assertTrue(listenerLatch.await(5, TimeUnit.SECONDS));
    assertTrue(task.isDone());

all think me at home!  Why, I wouldn't say anything about it,
even if I fell off the top of the house!' (Which was very likely
true.)

  Down, down, down.  Would the fall NEVER come to an end!  `I
wonder how many miles I've fallen by this time?' she said aloud.
`I must be getting somewhere near the centre of the earth.  Let
me see:  that would be four thousand miles down, I think--' (for,
you see, Alice had learnt several things of this sort in her

    final boolean[] called = new boolean[1];
    f.addCallback(
        new FutureCallback<String>() {
          @Override
          public void onSuccess(String result) {
            called[0] = true;
          }

          @Override
          public void onFailure(Throwable t) {}
        },
        directExecutor());
    assertThat(called[0]).isTrue();
  }

  }

  /**
   * Verify that the listener completes in a reasonable amount of time, and Asserts that the future
   * returns the expected data.
   *
   * @throws Throwable if the listener isn't called or if it resulted in a throwable or if the
   *     result doesn't match the expected value.
   */
  public void assertSuccess(Object expectedData) throws Throwable {

   * and then applying {@code function} to that value. Note that the resulting supplier will not
   * call {@code supplier} or invoke {@code function} until it is called.
   */
  public static <F extends @Nullable Object, T extends @Nullable Object> Supplier<T> compose(
      Function<? super F, T> function, Supplier<F> supplier) {
    return new SupplierComposition<>(function, supplier);
  }