void outputHistograms(PrintStream output) {
        boolean gotHistogram = false;
        for (Map.Entry<Identifier, UntypedMetric> entry : snapshot.entrySet()) {
            if (entry.getValue().getHistogram() == null) {
                continue;
            }
            gotHistogram = true;
            Histogram histogram = entry.getValue().getHistogram();
            Identifier id = entry.getKey();
            String metricIdentifier = getIdentifierString(id);
            output.println("# start of metric " + metricIdentifier);
            histogram.outputPercentileDistribution(output, 4, 1.0d, true);
            output.println("# end of metric " + metricIdentifier);
        }
        if (!gotHistogram) {
            output.println("# No histograms currently available.");
        }
    }
Convert simple metrics snapshots into jdisc state snapshots.

@author arnej27959
container-core/src/main/java/com/yahoo/metrics/simple/jdisc/SnapshotConverter.java