Documents\Article::setTitle PHP Метод

    public function setTitle($title)
    {
        $this->title = $title;
    }

 public function testDateRange()
 {
     $article1 = new Article();
     $article1->setTitle('test');
     $article1->setBody('test');
     $article1->setCreatedAt('1985-09-01 00:00:00');
     $article2 = new Article();
     $article2->setTitle('test');
     $article2->setBody('test');
     $article2->setCreatedAt('1985-09-02 00:00:00');
     $article3 = new Article();
     $article3->setTitle('test');
     $article3->setBody('test');
     $article3->setCreatedAt('1985-09-03 00:00:00');
     $article4 = new Article();
     $article4->setTitle('test');
     $article4->setBody('test');
     $article4->setCreatedAt('1985-09-04 00:00:00');
     $this->dm->persist($article1);
     $this->dm->persist($article2);
     $this->dm->persist($article3);
     $this->dm->persist($article4);
     $this->dm->flush();
     $this->dm->clear();
     $query = $this->dm->createQuery('Documents\\Article');
     $query->whereRange('createdAt', new \MongoDate(strtotime('1985-09-01')), new \MongoDate(strtotime('1985-09-04')));
     $articles = array_values($query->execute());
     $this->assertEquals(2, count($articles));
     $this->assertEquals('1985-09-02', $articles[0]->getCreatedAt()->format('Y-m-d'));
     $this->assertEquals('1985-09-03', $articles[1]->getCreatedAt()->format('Y-m-d'));
 }