@Test
public void testBackpressureViaRequest() {

    OnSubscribeRange o = new OnSubscribeRange(1, RxRingBuffer.SIZE);
    TestSubscriber<Integer> ts = new TestSubscriber<Integer>();
    ts.assertReceivedOnNext(Collections.<Integer> emptyList());
    ts.requestMore(1);
    o.call(ts);
    ts.assertReceivedOnNext(Arrays.asList(1));
    ts.requestMore(2);
    ts.assertReceivedOnNext(Arrays.asList(1, 2, 3));
    ts.requestMore(3);
    ts.assertReceivedOnNext(Arrays.asList(1, 2, 3, 4, 5, 6));
    ts.requestMore(RxRingBuffer.SIZE);
    ts.assertTerminalEvent();
}