//
//	content := etag.NewReader(r.Body, nil)
//
//	compressedContent := Compress(content)
//	encryptedContent := Encrypt(compressedContent)
//
//	// Now, we need an io.Reader that can access
//	// the ETag computed over the content.
//	reader := etag.Wrap(encryptedContent, content)
func Wrap(wrapped, content io.Reader) io.Reader {
	if t, ok := content.(Tagger); ok {
		return wrapReader{
			Reader: wrapped,
			Tagger: t,
		}
	}