docs: private JButton getHelpButton() {
          if (btnHelp == null) {
              btnHelp = new JButton();
              btnHelp.setBorder(null);
              btnHelp.setIcon(new ImageIcon(AbstractParamContainerPanel.class.getResource("/resource/icon/16/201.png"))); // help icon
              btnHelp.addActionListener(getShowHelpAction());
              btnHelp.setToolTipText(Constant.messages.getString("menu.help"));
          }
          
          return btnHelp;
      }