contentPane.insertRow(1);
contentPane.insertCell(1, 0);
header = new HeaderPart();
header.setAuthor(currentUser.getEmail());
menu = new MenuPart();
toolbar = new ToolbarPart();
editor = new EditorPart();
previewer = new PreviewerPart();
VerticalPanel headerPanel = new VerticalPanel();
headerPanel.setWidth("100%");
headerPanel.add(header);