ScheduledFuture<?> timer = timeoutFuture.timer;
          timeoutFuture.timer = null; // Don't include already elapsed delay in delegate.toString()
          String message = "Timed out";
          // This try-finally block ensures that we complete the timeout future, even if attempting
          // to produce the message throws (probably StackOverflowError from delegate.toString())
          try {
            if (timer != null) {

/** Unit test for {@link Streams}. */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class StreamsTest extends TestCase {
  /*
   * Full and proper black-box testing of a Stream-returning method is extremely involved, and is
   * overkill when nearly all Streams are produced using well-tested JDK calls. So, we cheat and
   * just test that the toArray() contents are as expected.
   */

 * the queue exceeds that value, the queue automatically removes its greatest element according to
 * its comparator (which might be the element that was just added). This is different from
 * conventional bounded queues, which either block or reject new elements when full.
 *
 * <p>This implementation is based on the <a
 * href="http://portal.acm.org/citation.cfm?id=6621">min-max heap</a> developed by Atkinson, et al.

              }
            }
          });
      try {
        future.get();
      } catch (Throwable t) {
        // Ignore, we just wanted to block.
      }
      String error = errorMessage.get();
      assertNull(error, error);
    }
    executor.shutdown();
  }

  /**

   * {@code tailSet} views.
   *
   * <pre>{@code
   * NavigableSet<E> set = synchronizedNavigableSet(new TreeSet<E>());
   *  ...
   * synchronized (set) {
   *   // Must be in the synchronized block
   *   Iterator<E> it = set.iterator();
   *   while (it.hasNext()) {
   *     foo(it.next());
   *   }
   * }
   * }</pre>
   *
   * <p>or:
   *
   * <pre>{@code

   * state: BLOCKED, WAITING, or TIMED_WAITING.
   */
  void waitForThreadToEnterWaitState(Thread thread, long timeoutMillis) {
    long startTime = System.nanoTime();
    for (; ; ) {
      Thread.State s = thread.getState();
      if (s == Thread.State.BLOCKED || s == Thread.State.WAITING || s == Thread.State.TIMED_WAITING)
        return;

   * cancelled without a call to {@code cancel}, such as by calling {@code
   * setFuture(cancelledFuture)}.
   *
   * <p>Beware of completing a future while holding a lock. Its listeners may do slow work or
   * acquire other locks, risking deadlocks.
   */
  @CanIgnoreReturnValue
  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    Object localValue = value;
    boolean rValue = false;

    // is likely to be a bug anyway.

    // N.B. All writes to the list and the next pointers must have happened before the above
    // synchronized block, so we can iterate the list without the lock held here.
    RunnableExecutorPair reversedList = null;
    while (list != null) {
      RunnableExecutorPair tmp = list;
      list = list.next;
      tmp.next = reversedList;

    // we try hard to make them robust in practice.  We could additionally try to add in a system
    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //
    // TODO(user): Consider using

   * future changes to it will alter the behavior of the predicate.
   *
   * <p>This method can technically accept any {@code Collection<?>}, but using a typed collection
   * helps prevent bugs. This approach doesn't block any potential users since it is always possible
   * to use {@code Predicates.<Object>in()}.
   *
   * @param target the collection that may contain the function input
   */