AssociationEntity2 example

    public function testValidateUniquenessNotToStringEntityWithAssociatedEntity()
    {
        $constraint = new UniqueEntity([
            'message' => 'myMessage',
            'fields' => ['single'],
            'em' => self::EM_NAME,
        ]);

        $entity1 = new SingleIntIdNoToStringEntity(1, 'foo');
        $associated = new AssociationEntity2();
        $associated->single = $entity1;
        $associated2 = new AssociationEntity2();
        $associated2->single = $entity1;

        $this->em->persist($entity1);
        $this->em->persist($associated);
        $this->em->flush();

        $this->validator->validate($associated, $constraint);

        $this->assertNoViolation();