protected function fixHeaders()
    {
        parent::fixHeaders();
        if (count($this->getChildren())) {
            $this->setHeaderParameter('Content-Type', 'charset', null);
            $this->setHeaderParameter('Content-Type', 'format', null);
            $this->setHeaderParameter('Content-Type', 'delsp', null);
        } else {
            $this->setCharset($this->userCharset);
            $this->setFormat($this->userFormat);
            $this->setDelSp($this->userDelSp);
        }
    }