@Override
        public void actionPerformed(ActionEvent e) {
          // This listener overrides one from BasicComboBoxUI$Actions
          // Close popup manually instead of default handler
          if (myEvaluateComboBox.getComboBox().isPopupVisible()) {
            myEvaluateComboBox.getComboBox().setPopupVisible(false);
          }
          else {
            addExpressionResultNode();
          }
        }
@Override
        public void actionPerformed(ActionEvent e)