/**
* Forces the mappable to be updated
*/
public void update() {
final MappableChangeEvent event = new MappableChangeEvent();
// The old value only needs to be a simple MapPoint to record the
// difference in latitude and longitude.
event.setOldState(_mapPointOldState);
// By sending the current object as the new state we ensure any changes
// in the position are respected, we also keep object creation down.
// However, if it is important that the information in the new state
// is synchronous it may be better to send a copy of the data so it
// isn't overwritten while being read by the MapField.
event.setNewState(this);
_eventManager.triggerEvent(event);
}