constraints = new GridBagConstraints();
// constraints.fill = GridBagConstraints.VERTICAL;
constraints.insets = new Insets( 2, 2, 2, 2 );
lessonTreePanel = new LessonTreePanel();
lessonTreePanel.setPreferredSize( new Dimension( 200, COMPONENT_HEIGHT ) );
flashcardPanel = new JPanel( new GridBagLayout() );
flashcardPanel = new JPanel( new BorderLayout() );