private function insertAtPosition($position)
{
if ($this->isInList()) {
$old_position = $this->getListifyPosition();
if ($position == $old_position) {
return;
}
$this->shufflePositionsOnIntermediateItems($old_position, $position);
} else {
$this->incrementPositionsOnLowerItems($position);
}
$this->setListPosition($position);
}