public function load(ObjectManager $manager)
{
$category1 = new Category();
$category1->setName("Science");
$category1->addBlog($manager->merge($this->getReference('blog-1')));
$category1->addBlog($manager->merge($this->getReference('blog-2')));
$category1->addBlog($manager->merge($this->getReference('blog-3')));
$manager->persist($category1);
$category2 = new Category();
$category2->setName("Business");
$category2->addBlog($manager->merge($this->getReference('blog-4')));
$category2->addBlog($manager->merge($this->getReference('blog-5')));
$manager->persist($category2);
$category3 = new Category();
$category3->setName("Tech");
$manager->persist($category3);
$manager->flush();
$this->addReference('category-1', $category1);
$this->addReference('category-2', $category2);
$this->addReference('category-3', $category3);
}
