class MetricbeatMetricReader extends AbstractReader<RawMetric, Metric> {

    @Override
    public Stream<Metric> read(RawMetric rm) {
        // 按 \n 分隔?
        String str = readUTF8(rm.getRawBody());
        return Arrays.stream(str.split("\n"))
                .flatMap(this::readline)
                .filter(Objects::nonNull);
    }

}