occupantsByOccupantUri.put(occupant.getOccupantUri(), occupant);
final XmppURI userUri = occupant.getUserUri();
if (userUri != null) {
occupantsByUserUri.put(userUri.getJID(), occupant);
}
eventBus.fireEventFromSource(new OccupantChangedEvent(ChangeType.added, occupant), this);
}