Gin框架下返回XML数据如何添加 Header或者DocType类信息

Question

通过c.XML 很容易返回结构化的数据，

c.XML(http.StatusOK, Response{
Code: errno.Code,
SubCode: errno.SubCode,
Msg: errno.Msg,
Data: Data
}
但直接这样返回是不包含XML header的:
<Response>

<Data></Data>

</Response>

const (
// Header is a generic XML header suitable for use with the output of Marshal.
// This is not automatically added to any output of this package, // it is provided as a convenience. Header = `<?xml version="1.0" encoding="UTF-8"?>` + "\n"
)
网上搜到的基本都是 marshal后字符拼接之类，想问下，有没有优雅的方式让返回包含类似Header，使得返回的结果为：

<?xml version="1.0" encoding="UTF-8"?>
<Response>

<Data></Data>

</Response>