protected function _params2string($params)
    {
        if (!count($params)) {
            return '';
        }
        $paramsPart = array();
        foreach ($params as $name => $value) {
            if (!$value && ('0' !== $value)) {
                continue;
            }
            $paramsPart[] = str_replace(array('{name}', '{value}'), array($name, urlencode($value)), $this->paramsPairStructure);
        }
        if (!count($paramsPart)) {
            return '';
        }
        return '/' . implode($this->paramsSeparator, $paramsPart);
    }