@Override
public void cleanupOnDelete(ICourse course) {
super.cleanupOnDelete(course);
CoursePropertyManager cpm = PersistingCoursePropertyManager.getInstance(course);
cpm.deleteNodeProperties(this, CONF_CANCEL_ENROLL_ENABLED);
DENManager denManager = DENManager.getInstance();
//empty List as first argument, so all dates for this course node are going to delete
denManager.persistDENSettings(new ArrayList(), course, this);
}