latencyMilliSec MetricName = "latency_ms"
	sentBytes       MetricName = "sent_bytes"
	totalBytes      MetricName = "total_bytes"
	usedBytes       MetricName = "used_bytes"
	writeBytes      MetricName = "write_bytes"
	wcharBytes      MetricName = "wchar_bytes"

	latencyMicroSec MetricName = "latency_us"
	latencyNanoSec  MetricName = "latency_ns"

	commitInfo  MetricName = "commit_info"

		err = msgp.WrapError(err, "ReplicationState")
		return
	}
	if z.Data == nil { // allownil: if nil
		err = en.WriteNil()
		if err != nil {
			return
		}
	} else {
		err = en.WriteBytes(z.Data)
		if err != nil {
			err = msgp.WrapError(err, "Data")
			return
		}
	}
	err = en.WriteInt(z.NumVersions)
	if err != nil {
		err = msgp.WrapError(err, "NumVersions")
		return