if (model.getTreeView() == null) model.createTreeView();
    void showTreeView(boolean b)    {        Container container = getContentPane();        if (b) {            JSplitPane treeViewPane = new JSplitPane();            treeViewPane.setOrientation(JSplitPane.HORIZONTAL_SPLIT);            treeViewPane.setOneTouchExpandable(true);            treeViewPane.setContinuousLayout(true);            treeViewPane.setLeftComponent(model.getTreeView());            treeViewPane.setRightComponent(mainPane);            container.remove(mainPane);            container.add(treeViewPane, BorderLayout.CENTER);        } else {            container.removeAll();            addToContainer(mainPane);        }        container.validate();        container.repaint();    }