protected function getTransport()
    {
        if (is_null($this->transport)) {
            $tao = \common_ext_ExtensionsManager::singleton()->getExtensionById('tao');
            $transport = $tao->getConfig(self::CONFIG_KEY);
            if (!is_object($transport) || !$transport instanceof Transport) {
                return false;
            }
            $this->transport = $transport;
        }
        return $this->transport;
    }