err = en.Append(0xa2, 0x49, 0x44)
		if err != nil {
			return
		}
		err = en.WriteBytes((z.VersionID)[:])
		if err != nil {
			err = msgp.WrapError(err, "VersionID")
			return
		}
		// write "DDir"
		err = en.Append(0xa4, 0x44, 0x44, 0x69, 0x72)
		if err != nil {
			return
		}
		err = en.WriteBytes((z.DataDir)[:])
		if err != nil {
			err = msgp.WrapError(err, "DataDir")
			return

	var buf bytes.Buffer
	for _, k := range headers {
		buf.WriteString(k)
		buf.WriteByte(':')
		switch k {
		case "host":
			buf.WriteString(req.URL.Host)
			fallthrough
		default:
			for idx, v := range headerMap[k] {
				if idx > 0 {
					buf.WriteByte(',')
				}
				buf.WriteString(v)
			}
			buf.WriteByte('\n')
		}
	}
	canonicalHeaders := buf.String()

	// Get signed headers.

	}
}

type readFromWriter struct {
	buf           []byte
	writeBytes    int
	readFromBytes int
}

func (w *readFromWriter) Write(p []byte) (int, error) {
	w.buf = append(w.buf, p...)
	w.writeBytes += len(p)
	return len(p), nil
}

func (w *readFromWriter) ReadFrom(r io.Reader) (int64, error) {
	b, err := io.ReadAll(r)

	var s strings.Builder
	if x&xlFlagFreeVersion != 0 {
		s.WriteString("FreeVersion")
	}
	if x&xlFlagUsesDataDir != 0 {
		if s.Len() > 0 {
			s.WriteByte(',')
		}
		s.WriteString("UsesDD")
	}
	if x&xlFlagInlineData != 0 {
		if s.Len() > 0 {
			s.WriteByte(',')
		}
		s.WriteString("Inline")
	}
	return s.String()
}

					if i == len(in) {
						break
					}
				}
				if len(old) == 0 {
					_, length := utf8.DecodeRune(in[i:])
					out.Write(in[i : i+length])
					i += length
				} else {
					out.WriteByte(in[i])
					i++
				}
			}
			if len(old) == 0 && n != 0 {
				out.Write(new)
			}
			return out.Bytes()
		}