private function _post($url, &$json)
    {
        curl_setopt($this->_curlHandle, CURLOPT_CUSTOMREQUEST, 'POST');
        return $this->_curlHelper($url, $json);
    }
private function _post($url, &$json)
    {
        curl_setopt($this->_curlHandle, CURLOPT_CUSTOMREQUEST, 'POST');
        return $this->_curlHelper($url, $json);
    }
private function _post ( $ url , & $ json ) { curl_setopt ( $ this -> _curlHandle , CURLOPT_CUSTOMREQUEST , 'POST' ) ; return $ this -> _curlHelper ( $ url , $ json ) ; }
Helper that performs a HTTP POST operation.

@param string $url  the URL to POST to
@param string $json the JSON payload

@return string the response
Helper that performs a HTTP POST operation .