In java I need to count items per key so i thought of using `ConcurrentMap` with key and as value to have `AtomicInteger` however I wonder if there is a better way. Its not a critical service, its just used for collecting stats, so i don't mind if i'm late 10 seconds with correct stats or something like this. So i wonder if there is a better practice for it in standard java concurrency, or whether i'm left again with dealing by myself with ConcurrentMap and with `AtomicInteger` (an example which could also solve the problem would be message passing maybe, if yes how could that help me?) (best would be with example...) something which would not have performance issues and would be safe as well, and easy to use, i don't mind about latency.