es.open();
EventUtil.dumpAll(mem, es);
node.getAckChecker().checkAcks();
assertEquals(1, node.getAckChecker().pending.size());
mem.open(); // resets index.
// send to collector, collector updates master state (bypassing flakeyness)
EventUtil.dumpAll(mem, ((EventSinkDecorator<EventSink>) es).getSink());
// agent gets state from master, updates it ack states
try {
node.getAckChecker().checkAcks();