public synchronized void incrAllCounters(Counters other) {

    for (Group otherGroup: other) {

      Group group = getGroup(otherGroup.getName());

      group.displayName = otherGroup.displayName;

      for (Counter otherCounter : otherGroup) {

        Counter counter = group.getCounterForName(otherCounter.getName());

        counter.displayName = otherCounter.displayName;

        counter.value += otherCounter.value;

      }

    }

  }