/**
* @param ObjectManager $manager
*/
public function load(ObjectManager $manager)
{
$lesson = new Lesson();
$lesson->setActive(true)->setDate(new \DateTime('2015-09-08'))->setDuration(60)->setLevel($this->getReference('level1'))->setStart(new \DateTime('18:15:00'));
$manager->persist($lesson);
$lesson = new Lesson();
$lesson->setActive(true)->setDate(new \DateTime('2015-09-15'))->setDuration(60)->setLevel($this->getReference('level1'))->setStart(new \DateTime('18:15:00'));
$manager->persist($lesson);
$lesson = new Lesson();
$lesson->setActive(true)->setDate(new \DateTime('2015-09-29'))->setDuration(60)->setLevel($this->getReference('level2'))->setStart(new \DateTime('18:15:00'));
$manager->persist($lesson);
$lesson = new Lesson();
$lesson->setActive(true)->setDate(new \DateTime('2015-09-17'))->setDuration(90)->setLevel($this->getReference('level3'))->setStart(new \DateTime('19:00:00'));
$manager->persist($lesson);
$manager->flush();
}