code: public function shiftSiblingsForRestore() {
      if ( is_null($this->getRight()) || is_null($this->getLeft()) ) return;
  
      $self = $this;
  
      $this->getConnection()->transaction(function() use ($self) {
        $lftCol = $self->getLeftColumnName();
        $rgtCol = $self->getRightColumnName();
        $lft    = $self->getLeft();
        $rgt    = $self->getRight();
  
        $diff = $rgt - $lft + 1;
  
        $self->newNestedSetQuery()->where($lftCol, '>=', $lft)->increment($lftCol, $diff);
        $self->newNestedSetQuery()->where($rgtCol, '>=', $lft)->increment($rgtCol, $diff);
      });
    }
docs: "Makes room" for the the current node between its siblings.
  
  @return void