ElggSession::start PHP Method

    public function start()
    {
        $result = $this->storage->start();
        $this->generateSessionToken();
        return $result;
    }

 public function testMigrate()
 {
     $session = new ElggSession(new Elgg_Http_MockSessionStorage());
     $session->start();
     $session->set('foo', 5);
     $id = $session->getId();
     $this->assertTrue($session->migrate());
     $this->assertTrue($session->has('foo'));
     $this->assertNotEquals($id, $session->getId());
     $this->assertTrue($session->has('__elgg_session'));
 }