*             incomplete and the {@code ListenableFuture} later completes normally, the
   *             listener runs in the thread that completes the {@code ListenableFuture}.
   *         <li>When a listener is attached to a {@code ListenableFuture} and the {@code
   *             ListenableFuture} gets cancelled, the listener runs immediately in the thread that

   *
   * <p>When selecting an executor, note that {@code directExecutor} is dangerous in some cases. See
   * the discussion in the {@link ListenableFuture#addListener ListenableFuture.addListener}
   * documentation.
   */
  public void add(Runnable runnable, Executor executor) {
    // Fail fast on a null. We throw NPE here because the contract of Executor states that it throws

/**
 * An abstract implementation of {@link ListenableFuture}, intended for advanced users only. More
 * common ways to create a {@code ListenableFuture} include instantiating a {@link SettableFuture},
 * submitting a task to a {@link ListeningExecutorService}, and deriving a {@code Future} from an
 * existing one, typically using methods like {@link Futures#transform(ListenableFuture,

                <copy toDir="${project.build.directory}/guava-gwt-sources">
                  <fileset dir="${project.build.directory}/guava-sources">
                    <include name="**/ListenableFuture.java" />
                  </fileset>
                </copy>
                <copy toDir="${project.build.directory}/guava-gwt-sources">
                  <fileset dir="${project.build.directory}/failureaccess-sources">