docs: public Map<Long, ClientStats> getStatsByConnection() {
          Map<Long, Map<String, ClientStats>> complete = getCompleteStats();
          Map<Long, ClientIOStats> completeIO = diffIO(m_currentIO, m_baselineIO);
          Map<Long, ClientStats> retval = new TreeMap<Long, ClientStats>();
          for (Entry<Long, Map<String, ClientStats>> e : complete.entrySet()) {
              ClientStats cs = ClientStats.merge(e.getValue().values());
              ClientIOStats cios = completeIO.get(e.getKey());
              if (cios != null) {
                  cs.m_bytesReceived = cios.m_bytesReceived;
                  cs.m_bytesSent = cios.m_bytesSent;
              }
              retval.put(e.getKey(), cs);
          }
          return retval;
      }