// set listener so function set gets updated if the checkboxes change
checkBox.setOnAction(new EventHandler<ActionEvent>() {
@Override
public void handle(ActionEvent event) {
if (((CheckBox) event.getSource()).isSelected()) {
functionSet.enableFunction(index);
} else {
functionSet.disableFunction(index);
}
gui.updateFunctionSelector();
revalidateParameters();