QTreeView::collapseAll and QTreeView::expandAll do not emit the collapsed and expanded signals

void QTreeView::expandAll()
{
    Q_D(QTreeView);
    d->viewItems.clear();
    d->expandedIndexes.clear();
    d->interruptDelayedItemsLayout();
    d->layout(-1);
    for (int i = 0; i < d->viewItems.count(); ++i) {
        if (d->viewItems[i].expanded)
            continue;
        d->viewItems[i].expanded = true;
        d->layout(i);
        QModelIndex idx = d->viewItems.at(i).index;
        d->expandedIndexes.insert(idx);
    }
    updateGeometries();
    d->viewport->update();
}

    d->expandedIndexes.insert(idx);
+ emit expanded(idx);