code: private void handleWaterMarkEvent(Event<T> waterMarkEvent) {
          long watermarkTs = waterMarkEvent.getTimestamp();
          List<Long> eventTs = windowManager.getSlidingCountTimestamps(lastProcessedTs, watermarkTs, count);
          for (long ts : eventTs) {
              evictionPolicy.setContext(ts);
              handler.onTrigger();
              lastProcessedTs = ts;
          }
      }
docs: Triggers all the pending windows up to the waterMarkEvent timestamp
  based on the sliding interval count.
  
  @param waterMarkEvent the watermark event