public function getEncType()
    {
        if ($this->encType) {
            return $this->encType;
        }

        if ($fields = $this->fields->dataFields()) {
            foreach ($fields as $field) {
                if ($field instanceof FileField) {
                    return self::ENC_TYPE_MULTIPART;
                }
            }
        }

        return self::ENC_TYPE_URLENCODED;
    }