public function deleteTreeItem($entityClass = '',
        $id)
    {
        if ($entityClass === '') {
            throw new Exception('messages.error.classNameNotProvided');
        }
        $entity = $this->findById($id);
        $difference = $entity->rgt - $entity->lft + 1;

        $deleteTree = '
                DELETE FROM ' . $entityClass . ' a
                WHERE a.lft >= ' . $entity->lft . '
                    AND a.rgt <= ' . $entity->rgt . '
            ';
        $qTree = $this->query($deleteTree);
        $qTree->execute();

        $updateLft = '
                UPDATE ' . $entityClass . ' a
                SET a.lft = a.lft - ' . $difference . '
                WHERE a.lft > ' . $entity->rgt . '
            ';
        $qLft = $this->query($updateLft);
        $qLft->execute();

        $updateRgt = '
                UPDATE ' . $entityClass . ' a
                SET a.rgt = a.rgt - ' . $difference . '
                WHERE a.rgt > ' . $entity->rgt . '
            ';
        $qRgt = $this->query($updateRgt);
        $qRgt->execute();
    }