store.update(key, "client1", new M2AwareStatisticalSummary(1, 2, 5, 0, 10, 6, 7), 4);
store.update(key, "client2", new M2AwareStatisticalSummary(2, 4, 8, 1, 15, 9, 5), 2);
assertEquals(2, store.markers().size());
assertTrue(store.markers().contains("client1"));
assertTrue(store.markers().contains("client2"));
final Counter counter1 = store.getCounters("client1").iterator().next();
assertEquals(4, counter1.getMaxConcurrency());
assertEquals(4, counter1.currentConcurrency().get());
assertEquals(5, counter1.getHits());