// create options
    static final int FILE_WRITE_THROUGH           = 0x00000002;
    static final int FILE_SEQUENTIAL_ONLY         = 0x00000004;
    static final int FILE_SYNCHRONOUS_IO_ALERT    = 0x00000010;
    static final int FILE_SYNCHRONOUS_IO_NONALERT = 0x00000020;

    // security flags
    static final int SECURITY_CONTEXT_TRACKING = 0x01;
    static final int SECURITY_EFFECTIVE_ONLY   = 0x02;

   * CacheBuilder#refreshAfterWrite}, or through a call to {@link LoadingCache#refresh}.
   *
   * <p>This implementation synchronously delegates to {@link #load}. It is recommended that it be
   * overridden with an asynchronous implementation when using {@link
   * CacheBuilder#refreshAfterWrite}.
   *
   * <p><b>Note:</b> <i>all exceptions thrown by this method will be logged and then swallowed</i>.

    // create options
    static final int FILE_WRITE_THROUGH = 0x00000002;
    static final int FILE_SEQUENTIAL_ONLY = 0x00000004;
    static final int FILE_SYNCHRONOUS_IO_ALERT = 0x00000010;
    static final int FILE_SYNCHRONOUS_IO_NONALERT = 0x00000020;

    // security flags
    static final int SECURITY_CONTEXT_TRACKING = 0x01;
    static final int SECURITY_EFFECTIVE_ONLY = 0x02;

   * CacheBuilder#refreshAfterWrite}, or through a call to {@link LoadingCache#refresh}.
   *
   * <p>This implementation synchronously delegates to {@link #load}. It is recommended that it be
   * overridden with an asynchronous implementation when using {@link
   * CacheBuilder#refreshAfterWrite}.
   *
   * <p><b>Note:</b> <i>all exceptions thrown by this method will be logged and then swallowed</i>.

   * executor}.
   *
   * @param listener the backing listener
   * @param executor the executor with which removal notifications are asynchronously executed
   */
  public static <K, V> RemovalListener<K, V> asynchronous(
      RemovalListener<K, V> listener, Executor executor) {
    checkNotNull(listener);
    checkNotNull(executor);
    return (RemovalNotification<K, V> notification) ->

public interface AsyncCallable<V extends @Nullable Object> {
  /**
   * Computes a result {@code Future}. The output {@code Future} need not be {@linkplain
   * Future#isDone done}, making {@code AsyncCallable} suitable for asynchronous derivations.
   *
   * <p>Throwing an exception from this method is equivalent to returning a failing {@link
   * ListenableFuture}.
   */
  ListenableFuture<V> call() throws Exception;

  /**
   * Returns an output {@code Future} to use in place of the given {@code input}. The output {@code
   * Future} need not be {@linkplain Future#isDone done}, making {@code AsyncFunction} suitable for
   * asynchronous derivations.
   *
   * <p>Throwing an exception from this method is equivalent to returning a failing {@code Future}.
   */
  ListenableFuture<O> apply(@ParametricNullness I input) throws Exception;

   * currently contains a value for {@code key}, and {@link CacheLoader#load} otherwise. Loading is
   * asynchronous only if {@link CacheLoader#reload} was overridden with an asynchronous
   * implementation.
   *
   * <p>Returns without doing anything if another thread is currently loading the value for {@code

    // We post the event, but our Executor will not deliver it until instructed.
    bus.post(EVENT);

    List<String> events = catcher.getEvents();
    assertTrue("No events should be delivered synchronously.", events.isEmpty());

    // Now we find the task in our Executor and explicitly activate it.
    List<Runnable> tasks = executor.getTasks();
    assertEquals("One event dispatch task should be queued.", 1, tasks.size());

 * ListenableFuture}</a>.
 *
 * <p>This class is GWT-compatible.
 *
 * <h3>Purpose</h3>
 *
 * <p>The main purpose of {@code ListenableFuture} is to help you chain together a graph of
 * asynchronous operations. You can chain them together manually with calls to methods like {@link
 * Futures#transform(ListenableFuture, com.google.common.base.Function, Executor) Futures.transform}