protected function getDocumentManager()
 {
     $config = new Configuration();
     $config->setProxyDir(sys_get_temp_dir() . '/JMSDoctrineTestProxies');
     $config->setProxyNamespace('JMS\\Tests\\Proxies');
     $config->setMetadataDriverImpl(new DoctrinePHPCRDriver(new AnnotationReader(), __DIR__ . '/../../Fixtures/DoctrinePHPCR'));
     $session = $this->getMock('PHPCR\\SessionInterface');
     return DocumentManager::create($session, $config);
 }