code: @Override
  	public final void setUUID(UUID id) {
  		final UUID oldId = getUUID();
  		if ((oldId != null && !oldId.equals(id)) || (oldId == null && id != null)) {
  			super.setUUID(oldId);
  			fireElementChanged();
  		}
  	}
docs: Set the unique identifier for element.
  
  <p>A Unique IDentifier (UID) must be unique for all the object instances.
  
  @param id is the new identifier
  @since 4.0