tags.add(new MetricsTag(MsInfo.Hostname, "host"));
Set<AbstractMetric> metrics = new HashSet<AbstractMetric>();
MetricsRecord record = new MetricsRecordImpl(MsInfo.Context, (long) 1, tags, metrics);
StringBuilder sb = new StringBuilder();
sink.appendPrefix(record, sb);
assertEquals(".NumActiveSources=foo.NumActiveSinks=bar.NumAllSinks=haa", sb.toString());
tags.set(0, new MetricsTag(MsInfo.Context, "some"));
sb = new StringBuilder();
sink.appendPrefix(record, sb);