in src/main/java/org/apache/sling/commons/metrics/internal/JSONReporter.java [132:142]
private JSONReporter(MetricRegistry registry,
PrintStream output, TimeUnit rateUnit, TimeUnit durationUnit, MetricFilter filter){
this.registry = registry;
this.filter = filter;
this.pw = new PrintWriter(output);
this.json = new JSONWriter(pw);
this.rateFactor = rateUnit.toSeconds(1);
this.rateUnit = calculateRateUnit(rateUnit);
this.durationFactor = 1.0 / durationUnit.toNanos(1);
this.durationUnit = durationUnit.toString().toLowerCase(Locale.US);
}