code: public void putResponse(Response<?> r) {
          synchronized (responseMap) {
              List<Response<?>> l = responseMap.get(r.getCorrelationId());
              if (l == null) {
                  l = new SortedResponseList();
                  responseMap.put(r.getCorrelationId(), l);
              }
              l.add(r);
          }
      }
docs: Internal use only - called by the processing engine
  
  @param r
  response to be put into the response map.