falling down a very deep well.

  Either the well was very deep, or she fell very slowly, for she
had plenty of time as she went down to look about her and to
wonder what was going to happen next.  First, she tried to look
down and make out what she was coming to, but it was too dark to
see anything; then she looked at the sides of the well, and
noticed that they were filled with cupboards and book-shelves;

            new AsyncCallable<String>() {
              @Override
              public ListenableFuture<String> call() throws Exception {
                // Make this executor terminate after this task so that the test can tell when
                // futureResult has received resultOfCombiner.
                executor.shutdown();
                callableBlocking.await();
                return resultOfCombiner;
              }

            new AsyncCallable<String>() {
              @Override
              public ListenableFuture<String> call() throws Exception {
                // Make this executor terminate after this task so that the test can tell when
                // futureResult has received resultOfCombiner.
                executor.shutdown();
                callableBlocking.await();
                return resultOfCombiner;
              }

falling down a very deep well.

  Either the well was very deep, or she fell very slowly, for she
had plenty of time as she went down to look about her and to
wonder what was going to happen next.  First, she tried to look
down and make out what she was coming to, but it was too dark to
see anything; then she looked at the sides of the well, and
noticed that they were filled with cupboards and book-shelves;

   * a later time.
   *
   * <p>Since this method uses {@code HashMap} instances internally, the keys of the supplied maps
   * must be well-behaved with respect to {@link Object#equals} and {@link Object#hashCode}.
   *
   * <p><b>Note:</b>If you only need to know whether two maps have the same mappings, call {@code
   * left.equals(right)} instead of this method.

     * performed at the front of each bin. This makes it easy to check changes, and also fast to
     * traverse. When nodes would otherwise be changed, new nodes are created to replace them. This
     * works well for hash tables since the bin lists tend to be short. (The average length is less
     * than two.)
     *
     * Read operations can thus proceed without locking, but rely on selected uses of volatiles to