sequentialGroup.addComponent(new JLabel("Choose an example to launch:"));
sequentialGroup.addComponent(new JButton(new ShowOctree()));
sequentialGroup.addComponent(new JButton(new ShowMathGraphs()));
sequentialGroup.addComponent(new JLabel("Choose an example to launch:"));
sequentialGroup.addComponent(new JButton(new ShowOctree()));
sequentialGroup.addComponent(new JButton(new ShowMathGraphs()));