assertEquals(4., counter2.getVariance(), 0);
assertEquals(9., counter2.getSum(), 0);
final Counter aggregate = store.getOrCreateCounter(key);
assertEquals(6, aggregate.getMaxConcurrency());
assertEquals(6, aggregate.currentConcurrency().get());
assertEquals(13, aggregate.getHits());
assertEquals(10., aggregate.getMin(), 0);
assertEquals(1., aggregate.getMax(), 0);
assertEquals(1.12089, aggregate.getStandardDeviation(), 0.001);
assertEquals(1.2564, aggregate.getVariance(), 0.001);