code: public static <V> ListenableFuture<V> immediateFailedFuture(Throwable throwable) {
      checkNotNull(throwable);
      return new ImmediateFailedFuture<V>(throwable);
    }
docs: Returns a {@code ListenableFuture} which has an exception set immediately upon construction.
  
  <p>The returned {@code Future} can't be cancelled, and its {@code isDone()} method always
  returns {@code true}. Calling {@code get()} will immediately throw the provided {@code
  Throwable} wrapped in an {@code ExecutionException}.