public function testFindByRefManySimple()
 {
     $user = new User();
     $group = new Group('group');
     $user->addGroupSimple($group);
     $this->dm->persist($user);
     $this->dm->persist($group);
     $this->dm->flush();
     $this->assertSame($user, $this->dm->getRepository(User::class)->findOneBy(['groupsSimple' => $group]));
 }