private <T, R> R testAvg(T[] values, Aggregation<String, T, R> aggregation) throws Exception { String mapName = randomMapName(); MultiMap<String, T> map = HAZELCAST_INSTANCE.getMultiMap(mapName); for (int i = 0; i < values.length; i++) { map.put("key-" + i, values[i]); } Supplier<String, T, T> supplier = Supplier.all(); return map.aggregate(supplier, aggregation); }