Following code run with optimistic caches:

start tx
put k, v1
put k, v2
put k, v3
commit

Would cause the PrepareCommand that is sent around to contain 3 PutKeyvalueCommands which is sub-optimal. What we can do is to only send the last written value (i.e. k v3) and ignore the previous two (reuse the code in AsyncCacheStore). Besides reducing the payload, from this would benefit the AtomicHashMaps which uses this code quite a lot and also the OptimisticLockingInterceptor which would not attempt to order the keys.

I guess this should be a feature that is disabled by default, as I don't think it is required in general. Might as well be not configurable, enabled by default feature. Comments?