private Map<String, List<PerfSample>> fetchResults(long clock) {
Map<String,List<PerfSample>> results = new HashMap<String, List<PerfSample>>();
// Grab and sort samples
for (int ln = 0; ln < listers.size(); ln++) {
QueryLister lister = listers.get(ln);
for (PerfSample sample : scanner.getPerfSamples(clock, lister)) {
QueryResult rslt = (QueryResult)sample.getResult();
String label = ObjectInspector.substitute(tmplLabel, rslt.getAttrs());
if (!results.containsKey(label)) {
results.put(label, new ArrayList<PerfSample>());