@Test
public void testEmptyStreamProducesZeros() {

    HystrixCommandKey key = HystrixCommandKey.Factory.asKey("CMD-Concurrency-A");
    stream = RollingCommandMaxConcurrencyStream.getInstance(key, 10, 500);
    stream.startCachingStreamValuesIfUnstarted();
    final CountDownLatch latch = new CountDownLatch(1);
    stream.observe().take(5).subscribe(getSubscriber(latch));
    //no writes
    try {
        assertTrue(latch.await(10000, TimeUnit.MILLISECONDS));
    } catch (InterruptedException ex) {
        fail("Interrupted ex");
    }
    assertEquals(0, stream.getLatestRollingMax());
}