@Override
    protected List<KeyValueScanner> createList(int capacity) {
      if (START_TEST.get()) {
        try {
          getScannerLatch.countDown();
          snapshotLatch.await();
        } catch (InterruptedException e) {
          throw new RuntimeException(e);
        }
      }
      return new ArrayList<>(capacity);
    }
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