//perf fix: only process elements between time and last processed - sampler duration
private void rebuildAggRow(GraphRowSimple row, long time, long duration) {
long key = row.getHigherKey(lastAggUpdateTime - duration - 1);
while (key < time && key != -1) {
GraphPanelChartSimpleElement elt = (GraphPanelChartSimpleElement) row.getElement(key);
elt.add(getAllThreadCount(key));
Long nextKey = row.getHigherKey(key);
if (nextKey != null) {
key = nextKey;
} else {