/** @return comboBox_axes */
  private JComboBox getComboBox_axes() {
    if (comboBox_axes == null) {
      comboBox_axes = new JComboBox();
      comboBox_axes.setModel(new DefaultComboBoxModel(new String[] {"X,Y", "X,Z", "Y,Z"}));
      comboBox_axes.setSelectedItem(TwoAxes3D.getAxes());
      comboBox_axes.addActionListener(
          new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
              TwoAxes3D.setAxes((String) comboBox_axes.getSelectedItem());
              fireActionEvent(
                  new ActionEvent(
                      TwoAxes3DSettingsPanel.this,
                      0,
                      SycamoreFiredActionEvents.UPDATE_AGREEMENTS_GRAPHICS.name()));
            }
          });
    }
    return comboBox_axes;
  }
 /** @return spinner_rotation */
 private JSpinner getSpinner_rotation() {
   if (spinner_rotation == null) {
     spinner_rotation = new JSpinner();
     spinner_rotation.setMaximumSize(new Dimension(80, 27));
     spinner_rotation.setMinimumSize(new Dimension(80, 27));
     spinner_rotation.setPreferredSize(new Dimension(80, 27));
     spinner_rotation.setModel(
         new SpinnerNumberModel(0.0, -Double.MAX_VALUE, Double.MAX_VALUE, 1));
     spinner_rotation.setValue(TwoAxes3D.getRotation());
     spinner_rotation.addChangeListener(
         new ChangeListener() {
           @Override
           public void stateChanged(ChangeEvent e) {
             TwoAxes3D.setRotation((Double) spinner_rotation.getValue());
             fireActionEvent(
                 new ActionEvent(
                     TwoAxes3DSettingsPanel.this,
                     0,
                     SycamoreFiredActionEvents.UPDATE_AGREEMENTS_GRAPHICS.name()));
           }
         });
   }
   return spinner_rotation;
 }