@Test
@Order(20)
public void queryByObjectParameter_readFromDatabase() {
	resetSecondLevelCache();
	queryByObjectParameter();
}

@Test
@Order(21)
public void queryByObjectParameter_readFromL2Cache() {
	queryByObjectParameter();

	// This fails because querying by object results in a cache miss every time in Hibernate 6.1.7.
	// This succeeds in Hibernate 5.6.15.
	assertThat(getSecondLevelHitCount()).isEqualTo(1L); 
}

private void queryByObjectParameter() {
	Session session = entityManager.unwrap(Session.class);

	Query<Parent> queryParent = session.createQuery("from Parent p where p.name = 'John'", Parent.class);
	List<Parent> p = queryParent.getResultList();

	Query<Child> queryChildren = session.createQuery("from Child c where c.parent = ?1", Child.class);
	queryChildren.setParameter(1, p.get(0));
	queryChildren.setCacheable(true);
	List<Child> c = queryChildren.getResultList();
}

private void resetSecondLevelCache() {
	Session session = entityManager.unwrap(Session.class);
	session.getSessionFactory().getCache().evictQueryRegion("default-query-results-region");
	session.getSessionFactory().getStatistics().clear();
}

private long getSecondLevelHitCount() {
	Session session = entityManager.unwrap(Session.class);
	Statistics stats = session.getSessionFactory().getStatistics();
	CacheRegionStatistics regionStats = stats.getDomainDataRegionStatistics("default-query-results-region");
	return regionStats.getHitCount();
}

Query<Child> queryChildren = session.createQuery("from Child c where c.parent.id = ?1", Child.class);
queryChildren.setParameter(1, p.get(0).getId());