/**
  * Append to operation internal handler
  * @param bool $append
  * @throws Exception
  */
 protected function insertIntoInternal($append)
 {
     $this->checkNode(false);
     $this->owner->setAttribute($this->parentAttribute, $this->node->getPrimaryKey());
     if ($this->sortable !== false) {
         if ($append) {
             $this->owner->moveLast();
         } else {
             $this->owner->moveFirst();
         }
     }
 }