Lookitsatravis\Listify\Listify::insertAtPosition PHP Метод

    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);
    }