private function stringToUtf($input)
    {
        if (is_array($input)) {
            $temp = array();
            foreach ($input as $key => $value) {
                $temp[$this->stringToUtf($key)] = $this->stringToUtf($value);
            }
            $input = $temp;
        } elseif (is_string($input)) {
            $input = iconv('iso-8859-15', 'utf-8', $input);
        }

        return $input;
    }