* won't be cleared as long as the enum constant is referenced somewhere, and the enum constant
     * is referenced somewhere for as long as the enum class is loaded. *Maybe in theory* the enum
     * class could be unloaded after the above call to `getEnumConstants` but before we call
     * `get()`, but that is vanishingly unlikely.
     */
    return ref == null ? Optional.absent() : Optional.fromNullable(enumClass.cast(ref.get()));
  }

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

 *       annotations that {@code ParametricNullness} was counteracting.
 * </ul>
 *
 * <p>This annotation is a temporary hack. We will remove it after <a
 * href="https://github.com/google/guava/issues/6126#issuecomment-1203145963">tools no longer need
 * it</a>.
 */
@GwtCompatible
@Retention(CLASS)
@Target({FIELD, METHOD, PARAMETER})

        // now. Or it could have an arbitrary last modified time set by the creator, but that's no
        // different than if another process set its last modified time to something else after we
        // created it here.
      }
    }
  }

  /**
   * Creates any necessary but nonexistent parent directories of the specified path. Note that if

        assertTrue(future.isCancelled());
        assertTrue(cancellationSuccess.get());
        // cancellation can interleave in 3 ways
        // 1. prior to setFuture
        // 2. after setFuture before set() on the future assigned
        // 3. after setFuture and set() are called but before the listener completes.
        if (!setFutureSetSuccess.get() || !setFutureCompletionSuccess.get()) {

    }

    // Close the writer to release its resources (such as deflaters).
    ignoreIoExceptions {
      writer.close()
    }

    // Cancel the socket to break out the reader thread, which will clean up after itself.
    ignoreIoExceptions {
      socket.cancel()
    }

    // Release the threads.
    writerQueue.shutdown()
    pushQueue.shutdown()
    settingsListenerQueue.shutdown()
  }