original_string: public function getRootId()
      {
          if (empty($this->hierarchy)) {
              throw new Exception\LogicException('The root item does not exist.');
          }
  
          reset($this->hierarchy);
          $id = key($this->hierarchy);
  
          return $id;
      }
code: public function getRootId()
      {
          if (empty($this->hierarchy)) {
              throw new Exception\LogicException('The root item does not exist.');
          }
  
          reset($this->hierarchy);
          $id = key($this->hierarchy);
  
          return $id;
      }
code_tokens: public function getRootId ( ) { if ( empty ( $ this -> hierarchy ) ) { throw new Exception \ LogicException ( 'The root item does not exist.' ) ; } reset ( $ this -> hierarchy ) ; $ id = key ( $ this -> hierarchy ) ; return $ id ; }
docstring: Returns the identifier of the root item
  
  @return string
  
  @throws Exception\LogicException if the root item does not exist
docstring_tokens: Returns the identifier of the root item