WatermarkCoalescer { public abstract long checkWmHistory(); private  WatermarkCoalescer(); abstract long queueDone(int queueIndex); abstract void observeEvent(int queueIndex); abstract long observeWm(int queueIndex, long wmValue); abstract long checkWmHistory(); abstract long coalescedWm(); abstract long topObservedWm(); static WatermarkCoalescer create(int queueCount); static final Watermark IDLE_MESSAGE; }
@Test public void when_nothingHappened_then_noWm() { assertEquals(Long.MIN_VALUE, wc.checkWmHistory()); }