for (int labelId : counters.keySet())
{
if (labels.containsId(labelId) && counters.containsKey(labelId)) {
labels.get(labelId).setCounters(counters.get(labelId));
} else if (labels.containsId(labelId) && !counters.containsKey(labelId)) {
// assume zeros for all counters if not yet initialised
labels.get(labelId).setCounters(new LabelCounters());
} else if (!labels.containsId(labelId) && counters.containsKey(labelId)) {
logger.warn("Found counters for label {}/{}, but label does not exist.", mailbox.getId(), labelId);
}