long delta = System.currentTimeMillis() - start;
res.addTiming("inject", "0", delta);
int i;
for (i = 0; i < depth; i++) { // generate new segment
start = System.currentTimeMillis();
String batchId = generator.generate(topN, System.currentTimeMillis(),
false, false);
delta = System.currentTimeMillis() - start;
res.addTiming("generate", i + "", delta);
if (batchId == null) {
LOG.info("Stopping at depth=" + i + " - no more URLs to fetch.");