public function getQueryString($majorProtocolVersion = null,
        $minorProtocolVersion = null)
    {
        $queryArray = array();

        foreach ($this->_params as $name => $value) {
            if (substr($name, 0, 1) == '_') {
                continue;
            }

            switch($name) {
                case 'location-radius':
                    if ($majorProtocolVersion == 1) {
                        require_once 'Zend/Gdata/App/VersionException.php';
                        throw new Zend_Gdata_App_VersionException("The $name " .
                            "parameter is only supported in version 2.");
                    }
                    break;

                case 'racy':
                    if ($majorProtocolVersion == 2) {
                        require_once 'Zend/Gdata/App/VersionException.php';
                        throw new Zend_Gdata_App_VersionException("The $name " .
                            "parameter is not supported in version 2. " .
                            "Please use 'safeSearch'.");
                    }
                    break;

                case 'safeSearch':
                    if ($majorProtocolVersion == 1) {
                        require_once 'Zend/Gdata/App/VersionException.php';
                        throw new Zend_Gdata_App_VersionException("The $name " .
                            "parameter is only supported in version 2. " .
                            "Please use 'racy'.");
                    }
                    break;

                case 'uploader':
                    if ($majorProtocolVersion == 1) {
                        require_once 'Zend/Gdata/App/VersionException.php';
                        throw new Zend_Gdata_App_VersionException("The $name " .
                            "parameter is only supported in version 2.");
                    }
                    break;

                case 'vq':
                    if ($majorProtocolVersion == 2) {
                        $name = 'q';
                    }
                    break;
            }

            $queryArray[] = urlencode($name) . '=' . urlencode($value);

        }
        if (count($queryArray) > 0) {
            return '?' . implode('&', $queryArray);
        } else {
            return '';
        }
    }