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