@Override
    protected void pushActiveToPipeline(MutableSegment active, boolean checkEmpty) {
      if (START_TEST.get()) {
        try {
          getScannerLatch.await();
        } catch (InterruptedException e) {
          throw new RuntimeException(e);
        }
      }

      super.pushActiveToPipeline(active, checkEmpty);
      if (START_TEST.get()) {
        snapshotLatch.countDown();
      }
    }
This test is for HBASE-26494, test the {@link RefCnt} behaviors in {@link ImmutableMemStoreLAB}
hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHStore.java