code: private JPanel getMainPanel() {
      if (mainPanel == null) {
        mainPanel = new JPanel();
        mainPanel.setLayout(new GridBagLayout());
  
        GridBagConstraints c = new GridBagConstraints();
        c.insets = new Insets(5, 5, 5, 5);
        c.fill = GridBagConstraints.HORIZONTAL;
  
        c.gridx = 0;
        c.gridy = 0;
        c.weightx = 0.0D;
        mainPanel.add(new JLabel("Host"), c);
  
        c.gridx = 1;
        c.weightx = 1.0D;
        mainPanel.add(getHostField(), c);
  
        c.gridx = 0;
        c.gridy = 1;
        c.weightx = 0.0D;
        mainPanel.add(new JLabel("User"), c);
  
        c.gridx = 1;
        c.weightx = 1.0D;
        mainPanel.add(getUserField(), c);
  
        c.gridx = 0;
        c.gridy = 2;
        c.weightx = 0.0D;
        mainPanel.add(new JLabel("Password"), c);
  
        c.gridx = 1;
        c.weightx = 1.0D;
        mainPanel.add(getPasswordField(), c);
  
        c.gridx = 0;
        c.gridy = 3;
        c.weightx = 1.0D;
        c.gridwidth = 2;
        mainPanel.add(getRememberPasswordCheckBox(), c);
  
        c.gridx = 0;
        c.gridy = 4;
        c.weightx = 1.0D;
        c.weighty = 1.0D;
        c.gridwidth = 2;
        mainPanel.add(new JPanel(), c);
      }
      return mainPanel;
    }
docs: This method initializes mainPanel
  
  @return javax.swing.JPanel