protected function separateParams($params)
    {
        $this->paramsDB = array();
        $this->paramsSys = Config::get('configsys');
        foreach ($params as $name => $value) {
            if (substr($name, 0, 1) === '_') {
                $name = substr($name, 1);
                if (!array_key_exists($name, $this->paramsSys)) {
                    throw new ConfigSys('Unknown system param "'.$name.'"');
                }
                $this->paramsSys[$name] = $value;
            } else {
                $this->paramsDB[$name] = $value;
            }
        }
    }