* {@code [1]} and {@code [1, 1]}).
   */
  // Note: 90% of the time we don't add type parameters or wildcards that serve only to "tweak" the
  // desired return type. However, *nested* generics introduce a special class of problems that we
  // think tip it over into being worthwhile.
  public static <T extends @Nullable Object, S extends T> Comparator<Iterable<S>> lexicographical(
      Comparator<T> comparator) {

   *       available even under older version.
   *   <li>Any property may be cleared through APIs like {@link System#clearProperty}.
   *   <li>Unusual environments like GWT may have their own special handling of system properties.
   * </ul>
   *
   * <p>Note that {@code StandardSystemProperty} does not provide constants for more recently added
   * properties, including:
   *
   * <ul>

   *
   * <p>Consider normalizing your string references with {@link #nullToEmpty}. If you do, you can
   * use {@link String#isEmpty()} instead of this method, and you won't need special null-safe forms
   * of methods like {@link String#toUpperCase} either. Or, if you'd like to normalize "in the other
   * direction," converting empty strings to {@code null}, you can use {@link #emptyToNull}.
   *

    static final Logger log = Logger.getLogger(ExecutionListCAS.class.getName());

    private static final sun.misc.Unsafe UNSAFE;
    private static final long HEAD_OFFSET;

    /**
     * A special instance of {@link RunnableExecutorPair} that is used as a sentinel value for the
     * bottom of the stack.
     */
    private static final RunnableExecutorPair NULL_PAIR = new RunnableExecutorPair(null, null);

    // Valid 4 byte.
    assertWellFormed(0xF0, 0xA4, 0xAD, 0xA2);
    // Bad trailing bytes
    assertNotWellFormed(0xF0, 0xA4, 0xAD, 0x7F);
    assertNotWellFormed(0xF0, 0xA4, 0xAD, 0xC0);
    // Special cases for byte2
    assertNotWellFormed(0xF0, 0x8F, 0xAD, 0xA2);
    assertNotWellFormed(0xF4, 0x90, 0xAD, 0xA2);
  }

  /** Tests some hard-coded test cases. */
  public void testSomeSequences() {
    // Empty

  public void testMaximalWeakStripedLock() {
    Striped<Lock> stripedLock = Striped.lazyWeakLock(Integer.MAX_VALUE);
    for (int i = 0; i < 10000; i++) {
      stripedLock.get(new Object()).lock();
      // nothing special (e.g. an exception) happens
    }
  }

  public void testBulkGetReturnsSorted() {
    for (Striped<?> striped : allImplementations()) {
      Map<Object, Integer> indexByLock = Maps.newHashMap();

     * we can override it in our non-null-guaranteeing subtypes to present a better signature to
     * their users.
     *
     * However, the checker *we* use has this special knowledge about `Collection.toArray()` anyway,
     * so in our implementation code, we can rely on that. That's why the expression below
     * type-checks.
     */
    return super.toArray();
  }

      implements Supplier<T>, Serializable {
    final Supplier<T> delegate;
    final long durationNanos;
    @CheckForNull transient volatile T value;
    // The special value 0 means "not yet initialized".
    transient volatile long expirationNanos;

    ExpiringMemoizingSupplier(Supplier<T> delegate, long durationNanos) {
      this.delegate = delegate;

   * been interrupted and is waiting to reacquire the lock while still registered in activeGuards,
   * in which case the signal is a no-op, and the bigger-picture signal is lost unless interrupted
   * threads take special action by participating in the signal-passing game.
   */

  /*
   * Timeout handling is intricate, especially given our ambitious goals:

     * that users *can* pass null arguments to Joiner, we annotate it as if it always tolerates null
     * inputs, rather than as if it never tolerates them.
     *
     * We rely on checkers to implement special cases to catch dangerous calls to join(), etc. based
     * on what they know about the particular Joiner instances the calls are performed on.
     *