xlHeaderVersion = 2
	xlMetaVersion   = 3
)

func decodeXLHeaders(buf []byte) (versions int, b []byte, e error) {
	hdrVer, buf, e := msgp.ReadUintBytes(buf)
	if e != nil {
		return 0, buf, e
	}
	metaVer, buf, e := msgp.ReadUintBytes(buf)
	if e != nil {
		return 0, buf, e
	}
	if hdrVer > xlHeaderVersion {
		return 0, buf, fmt.Errorf("decodeXLHeaders: Unknown xl header version %d", metaVer)
	}

	headerVer, metaVer uint
}

func decodeXLHeaders(buf []byte) (x xlHeaders, b []byte, err error) {
	x.headerVer, buf, err = msgp.ReadUintBytes(buf)
	if err != nil {
		return x, buf, err
	}
	x.metaVer, buf, err = msgp.ReadUintBytes(buf)
	if err != nil {
		return x, buf, err
	}
	if x.headerVer > xlHeaderVersion {
		return x, buf, fmt.Errorf("decodeXLHeaders: Unknown xl header version %d", x.headerVer)
	}

		return 0, 0, 0, buf, fmt.Errorf("decodeXLHeaders: Unknown xl header version %d", hdrVer)
	}
	if metaVer > xlMetaVersion {
		return 0, 0, 0, buf, fmt.Errorf("decodeXLHeaders: Unknown xl meta version %d", metaVer)
	}
	versions, buf, err = msgp.ReadIntBytes(buf)
	if err != nil {
		return 0, 0, 0, buf, err
	}
	if versions < 0 {
		return 0, 0, 0, buf, fmt.Errorf("decodeXLHeaders: Negative version count %d", versions)
	}