for (final Object object : list) {
if (object instanceof Listheader) {
final Listheader lheader = (Listheader) object;
if (lheader.getSortAscending() != null || lheader.getSortDescending() != null) {
lheader.addEventListener("onSort", onSortEventListener);
}
}
}
listBox.setModel(this);
}