@Test
public void testCancelClientCall() throws Exception {

  CountDownLatch latch = new CountDownLatch(1);
  MoneyObserver moneyObserver = new MoneyObserver(false, latch);
  streamingCallable.call(ASYNC_REQUEST, moneyObserver);
  moneyObserver.controller.cancel();
  moneyObserver.controller.request(1);
  latch.await(500, TimeUnit.MILLISECONDS);
  Truth.assertThat(moneyObserver.error).isInstanceOf(CancellationException.class);
  Truth.assertThat(moneyObserver.error).hasMessageThat().isEqualTo("User cancelled stream");
}