void merge(Bucket other, boolean otherIsNewer) {
        LazySet<String> malformedMetrics = LazySet.newHashSet();
        for (Map.Entry<Identifier, UntypedMetric> entry : other.values.entrySet()) {
            String metricName = entry.getKey().getName();
            try {
                if (!malformedMetrics.contains(metricName)) {
                    get(entry.getKey(), entry.getValue()).merge(entry.getValue(), otherIsNewer);
                }
            } catch (IllegalArgumentException e) {
                log.log(Level.WARNING, "Problems merging metric " + metricName + ", possibly ignoring data.");
                // avoid spamming the log if there are a lot of mismatching
                // threads
                malformedMetrics.add(metricName);
            }
        }
    }
An aggregation of data which is only written to from a single thread.

@author Steinar Knutsen
container-core/src/main/java/com/yahoo/metrics/simple/Bucket.java