public function testGetChildObject()
{
ConcreteArticleQuery::create()->deleteAll();
ConcreteQuizzQuery::create()->deleteAll();
ConcreteContentQuery::create()->deleteAll();
$content = new ConcreteContent();
$content->save();
$this->assertNull($content->getChildObject());
$article = new ConcreteArticle();
$article->save();
$content = $article->getConcreteContent();
$this->assertEquals($article, $content->getChildObject());
}
