question: protected final void fireIndexedPropertyChange ( String propertyName , int index , Object oldValue , Object newValue ) { PropertyChangeSupport aChangeSupport = this . changeSupport ; if ( aChangeSupport == null ) { return ; } aChangeSupport . fireIndexedPropertyChange ( propertyName , index , oldValue , newValue ) ; }
target:  Report a bound indexed property update to any registered listeners.<p> No event is fired if old and new values are equal and non-null.