question: public void removeVetoableChangeListener ( VetoableChangeListener listener ) { if ( listener != null ) { synchronized ( this ) { if ( vetoableSupport != null ) { vetoableSupport . removeVetoableChangeListener ( listener ) ; } } } }
target:  Removes a VetoableChangeListener from the listener list. This method should be used to remove the VetoableChangeListeners that were registered for all vetoable properties of this class. <p> If listener is null, no exception is thrown and no action is performed.