assertTrue("Callback should be invoked", latch.await(10, TimeUnit.SECONDS));
        assertNull("Received response should be null", received.get());
    }

    @Test
    public void test_rejectWithNullError() throws Exception {
        final Deferred<SuggestResponse> deferred = new Deferred<>();
        final AtomicReference<Throwable> received = new AtomicReference<>();