public class FrequencyCounter {

     private final ConcurrentHashMap<Integer,Long> frequencenyMap = new ConcurrentHashMap<>();

     public void processRequest(Request request){
         frequencenyMap.merge(request.type, 0L, (v, d) -> v+1);
     }

     public void clearMap(){
         frequencenyMap.clear();
     }

     public Map<Integer,Long> getMap(){
         return ImmutableMap.copyOf(frequencenyMap);
     }
}