private function valuesToFormParameters($values, $parent)
    {
        $ret = array();
        foreach ($values as $key => $value) {
            if (null !== $parent) {
                $keyName = sprintf('%s[%s]', $parent, $key);
            } else {
                $keyName = $key;
            }
            if (is_scalar($value)) {
                $ret[$keyName] = $value;
            } else {
                $ret = array_merge($ret, $this->valuesToFormParameters($value, $keyName));
            }
        }
        return $ret;
    }