public function add_child(Model_Comment $child)
{
$children = (array) $this->get('children');
$orphans = (array) $this->get('orphans');
if ($child->get('parent') != $this->get_id()) {
$orphans[$child->get_id()] = $child;
} else {
$children[$child->get_id()] = $child;
}
$this->search_parents($children, $orphans);
$this->set('children', $children);
$this->set('orphans', $orphans);
}
