public function definition_after_data() {
        $mform = $this->_form;
        $filterstartdate = $mform->getElement('filterstartdate')->getValue();
        $filterenddate = $mform->getElement('filterenddate')->getValue();
        if (!empty($filterstartdate['enabled']) || !empty($filterenddate['enabled'])) {
            $mform->setExpanded('filterheader', true);
        }
    }