PHPUnit test recomendations

Question

This is my first PHPUnit test with mocks, for a Symfony 3 project. Can anyone give me some advice about this code?

class CourierManager extends BaseManager
{
    /**
     * @param Courier $courier
     */
    public function create (Courier $courier) : void
    {
        $this->em->persist($courier);
        $this->em->flush();
    }

    /**
     * @param Courier $courier
     */
    public function update (Courier $courier) : void
    {
        $this->em->flush();
    }

    /**
     * @param $phone
     * @return null|Courier
     */
    public function findByPhone (string $phone) : ?Courier
    {
        return $this->repository->findOneByPhone($phone);
    }
}

BaseManager __construct method:

    public function __construct (EntityManager $entityManager,  $repositoryClass, Container $container)
    {
        $this->em = $entityManager;
        $this->repository = $entityManager->getRepository($repositoryClass);
        $this->container = $container;
        $this->entity = Order::class;
    }

And CourierManagerTest:

class CourierManagerTest extends \PHPUnit_Framework_TestCase
    {
        /**
         * @var EntityManager
         */
        private $em;

        /**
         * @var Container
         */
        private $container;

        /**
         * @var EntityRepository
         */
        private $repository;

        /**
         * @var CourierManager
         */
        private $manager;

        private static $courierClass = Courier::class;

        public function setUp () : void
        {
            $this->em = $this->getMockBuilder(EntityManager::class)->disableOriginalConstructor()->getMock();
            $this->em->expects($this->any())->method('persist')
                ->with($this->isInstanceOf(static::$courierClass))
            ;

            $this->repository = $this->getMockBuilder(EntityRepository::class)->disableOriginalConstructor()->getMock();

            $this->em->expects($this->any())->method('flush');
            $this->em->expects($this->any())->method('getRepository')->with($this->equalTo('AppBundle:Courier'))->will($this->returnValue($this->repository));

            $this->container = $this->getMockBuilder(Container::class)->getMock();
            $this->manager = new CourierManager($this->em, 'AppBundle:Courier', $this->container);
        }

        public function testCreate () : void
        {
            $this->manager->create($this->getCourier());
        }

        public function testFindByPhone () : void
        {
            $this->manager->findByPhone('1234567890');
        }

        private function getCourier () : Courier
        {
            return new static::$courierClass();
        }
    }