public function testMarkRead()
 {
     /** @var NotificationInterface $notification */
     $notification = $this->getMockBuilder(NotificationInterface::class)->setMethods(['getId', 'getText', 'getDate', 'getUser', 'getRead', 'setRead'])->getMock();
     $notification->expects($this->at(0))->method('setRead')->with(true);
     $this->objectManager->expects($this->at(0))->method('persist')->with($notification);
     $this->objectManager->expects($this->at(0))->method('flush');
     $result = $this->mapper->markRead($notification);
     $this->assertTrue($result);
 }