protected function add_grade_notices() {
        if (has_capability('mod/assign:grade', $this->get_context()) && get_config('assign', 'has_rescaled_null_grades_' . $this->get_instance()->id)) {
            $link = new \moodle_url('/mod/assign/view.php', array('id' => $this->get_course_module()->id, 'action' => 'fixrescalednullgrades'));
            \core\notification::warning(get_string('fixrescalednullgrades', 'mod_assign', ['link' => $link->out()]));
        }
    }