/**
* Invalides the current value so that the next invocation of <code>createValue</code> will ask
* for the property again.
*/
public void invalidate() {
if (pcl != null) {
toolkit.removePropertyChangeListener(getKey(), pcl);
toolkit = null;
pcl = null;
value = null;
}
}
void dispose() {
kit.removePropertyChangeListener(key, this);
}