docs: protected final void firePrimitiveChanged(String propertyName, Object oldValue, Object newValue) {
  		final BusChangeEvent event = new BusChangeEvent(
  				// source of the event
  				this,
  				// type of the event
  				BusChangeEventType.change(getClass()),
  				// subobject
  				this,
  				// index in parent
  				indexInParent(),
  				propertyName,
  				oldValue,
  				newValue);
  		firePrimitiveChanged(event);
  	}