public static State OverlayOnEventStoreList(ImList <Event> eventList, State state)
{
var eventStoreList = Store.GetEventStoreList(state);
return(Store.UpdateEventStoreList(
eventList
& Im.Overlay((evnt1, evnt2) => evnt1.Equals(evnt2), eventStoreList)
& Im.Sort
, state
));
}