protected function parseResponseCodes()
{
$responseCodes = explode('&', $this->response);
$codes = array();
foreach ($responseCodes as $key => $value) {
$value = urldecode($value);
$valueAry = explode('=', $value);
$codes[$valueAry[0]] = !empty($valueAry[1]) ? $valueAry[1] : null;
}
return $codes;
}