private function _calculateStringToSignV2(array $parameters) {
        $data = 'POST';
        $data .= "\n";
        $endpoint = parse_url ($this->_config['ServiceURL']);
        $data .= $endpoint['host'];
        $data .= "\n";
        $uri = array_key_exists('path', $endpoint) ? $endpoint['path'] : null;
        if (!isset ($uri)) {
        	$uri = "/";
        }
		$uriencoded = implode("/", array_map(array($this, "_urlencode"), explode("/", $uri)));
        $data .= $uriencoded;
        $data .= "\n";
        uksort($parameters, 'strcmp');
        $data .= $this->_getParametersAsString($parameters);
        return $data;
    }