code: public function descendantsAndSelf() {
      return $this->newNestedSetQuery()
                  ->where($this->getLeftColumnName(), '>=', $this->getLeft())
                  ->where($this->getLeftColumnName(), '<', $this->getRight());
    }
docs: Scope targeting itself and all of its nested children.
  
  @return \Illuminate\Database\Query\Builder