Baum\Node::leaves PHP Метод

    public function leaves()
    {
        $grammar = $this->getConnection()->getQueryGrammar();
        $rgtCol = $grammar->wrap($this->getQualifiedRightColumnName());
        $lftCol = $grammar->wrap($this->getQualifiedLeftColumnName());
        return $this->descendants()->whereRaw($rgtCol . ' - ' . $lftCol . ' = 1');
    }