/**
  * Extend to start listening to the models if necessary.
  *
  * @see org.eclipse.persistence.tools.workbench.utility.Model#addListChangeListener(String,
  *     ListChangeListener)
  */
 public synchronized void addListChangeListener(String listName, ListChangeListener listener) {
   if (listName == VALUE && this.hasNoListeners()) {
     this.engageModels();
   }
   super.addListChangeListener(listName, listener);
 }
 /**
  * Extend to start listening to the models if necessary.
  *
  * @see
  *     org.eclipse.persistence.tools.workbench.utility.Model#addListChangeListener(ListChangeListener)
  */
 public synchronized void addListChangeListener(ListChangeListener listener) {
   if (this.hasNoListeners()) {
     this.engageModels();
   }
   super.addListChangeListener(listener);
 }