protected function _before()
 {
     if (!extension_loaded('MongoDB')) {
         $this->markTestSkipped("MongoDB extension not loaded, test skipped");
         return;
     }
     Di::reset();
     $di = new DI();
     $di->set('mongo', function () {
         $mongo = new MongoClient('mongodb://' . TEST_MONGODB_HOST . ':' . TEST_MONGODB_PORT);
         return $mongo->selectDatabase('phalcon_test');
     });
     $di->set('collectionManager', function () {
         return new Manager();
     });
 }