protected function _bufferResponseLines(array $responseLines)
    {
        $response = [];
        foreach ($responseLines as $responseLine) {
            if (preg_match('/^(\d{3})(?:[ -]+(.*))?$/', $responseLine, $match)) {
                $response[] = [
                    'code' => $match[1],
                    'message' => isset($match[2]) ? $match[2] : null
                ];
            }
        }
        $this->_lastResponse = array_merge($this->_lastResponse, $response);
    }