@Override
      public void propertyChange(PropertyChangeEvent evt) {
        if (evt.getOldValue() != null) {
          ((TableColumnModel)evt.getOldValue()).getSelectionModel().removeListSelectionListener(selectionListener);
        }
        if (evt.getNewValue() != null) {
          ((TableColumnModel)evt.getNewValue()).getSelectionModel().addListSelectionListener(selectionListener);
        }
      }
@Override
      public void propertyChange(PropertyChangeEvent evt)