/**
  * delete link between current node and neighbor at index $pNeighborIndex
  * @param integer $pNeighborIndex
  * @return boolean|Node
  */
 protected function _deleteNeighborLinkAt($pNeighborIndex)
 {
     $lOldNeighbor = parent::_deleteNeighborLinkAt($pNeighborIndex);
     if ($lOldNeighbor) {
         $lOldNeighbor->deleteNeighbor($this->mCurrentNode);
     }
     return $lOldNeighbor;
 }