/**
  * (non-PHPdoc)
  * @see \InoOicServer\OpenIdConnect\Response\AbstractResponse::getHttpResponse()
  * @return \Zend\Http\Response
  */
 public function getHttpResponse()
 {
     $httpResponse = parent::getHttpResponse();
     $httpResponse->getHeaders()->addHeaders(array('Content-Type' => 'application/json'));
     if ($this->isError()) {
         $httpResponse->setStatusCode($this->_errorHttpStatusCode);
         $httpResponse->setContent($this->_createErrorResponseContent());
     } else {
         $httpResponse->setContent($this->_createResponseContent());
     }
     return $httpResponse;
 }