public function error(RESTfulAPI_Error $error)
{
$answer = new SS_HTTPResponse();
$body = $this->serializer->serialize($error->body);
$answer->setBody($body);
$answer->setStatusCode($error->code, $error->message);
$answer->addHeader('Content-Type', $this->serializer->getcontentType());
$answer = $this->setAnswerCORS($answer);
// save controller's response then return/output
$this->response = $answer;
return $answer;
}