this.appendButton = screen.findNiftyControl("appendButton", Button.class);
this.removeSelectionButton = screen.findNiftyControl("removeSelectionButton", Button.class);
this.selectedIndices = screen.findNiftyControl("selectedIndices", Label.class);
// just add some items to the listbox
listBox.addItem(new JustAnExampleModelClass("You can add more lines to this ListBox."));
listBox.addItem(new JustAnExampleModelClass("Use the append button to do this."));
multiSelectionCheckBox.uncheck();
disableSelectionCheckBox.uncheck();
forceSelectionCheckBox.uncheck();
addTextField.setText("");
}