protected function trigger_on_change() {
        $driver = $this->session->getDriver();
        if ($driver instanceof \Moodle\BehatExtension\Driver\MoodleSelenium2Driver) {
            $driver->triggerSynScript(
                $this->field->getXPath(),
                "Syn.trigger('change', {}, {{ELEMENT}})"
            );
        }
    }