public function testOneToOneRaceFlush(EntityManager $em)
{
$user = new User();
$user->setId(101)->setName('Steven');
$address = new Address();
$address->setId(501)->setStreet('Toast St');
$user->setAddress($address);
$em->persist($user)->flush()->persist($address)->flush();
/** @var User|OrmProxyInterface $r_user */
$r_user = $em->retrieve(User::class, 101);
$this->assertEquals('Steven', $r_user->getName());
// Should make DB query here
$r_address = $r_user->getAddress();
$this->assertTrue($r_address instanceof Address);
$this->assertTrue($r_address instanceof OrmProxyInterface);
}