@Test
public void testHappyPath() throws InterruptedException, ExecutionException {

  ApiFuture<String> result = callable.futureCall("request");
  MockServerStreamingCall<String, String> call = upstream.popLastCall();
  Truth.assertThat(call.getController().isAutoFlowControlEnabled()).isFalse();
  Truth.assertThat(call.getController().popLastPull()).isEqualTo(1);
  call.getController().getObserver().onResponse("response");
  Truth.assertThat(result.get()).isEqualTo("response");
  Truth.assertThat(call.getController().getObserver()).isNotNull();
}