func LimitFromMetadata(md metadata.MD) (uint64, error) {
	limit, ok := md["limit"]
	if !ok || len(limit) == 0 {
		return 0, nil
	}
	return strconv.ParseUint(limit[0], 10, 64)
}
func LimitFromMetadata(md metadata.MD) (uint64, error) {
	limit, ok := md["limit"]
	if !ok || len(limit) == 0 {
		return 0, nil
	}
	return strconv.ParseUint(limit[0], 10, 64)
}
// LimitFromMetadata gets the limit from the metadata