original_string: public function setDriver(\BearFramework\App\IDataDriver $driver): self
      {
          if ($this->driver !== null) {
              throw new \Exception('A data driver is already set!');
          }
          $this->driver = $driver;
          if ($this->filenameProtocol !== null) {
              \BearFramework\Internal\DataItemStreamWrapper::$environment[$this->filenameProtocol] = [$this, $driver];
          }
          return $this;
      }
code: public function setDriver(\BearFramework\App\IDataDriver $driver): self
      {
          if ($this->driver !== null) {
              throw new \Exception('A data driver is already set!');
          }
          $this->driver = $driver;
          if ($this->filenameProtocol !== null) {
              \BearFramework\Internal\DataItemStreamWrapper::$environment[$this->filenameProtocol] = [$this, $driver];
          }
          return $this;
      }
code_tokens: public function setDriver ( \ BearFramework \ App \ IDataDriver $ driver ) : self { if ( $ this -> driver !== null ) { throw new \ Exception ( 'A data driver is already set!' ) ; } $ this -> driver = $ driver ; if ( $ this -> filenameProtocol !== null ) { \ BearFramework \ Internal \ DataItemStreamWrapper :: $ environment [ $ this -> filenameProtocol ] = [ $ this , $ driver ] ; } return $ this ; }
docstring: Sets a new data driver.
  
  @param \BearFramework\App\IDataDriver $driver The data driver to use for data storage.
  @return self Returns a reference to itself.
  @throws \Exception
docstring_tokens: Sets a new data driver .