core/modules/admin/model/MenuCollection.php
<?php
class MenuCollection extends Ajde_Collection_With_I18n
{
public function filterByParent($menuId)
{
if ($menuId instanceof MenuModel) {
$menuId = $menuId->getPK();
}
$this->addFilter(new Ajde_Filter_Where('parent', Ajde_Filter::FILTER_EQUALS, $menuId));
return $this;
}
}