original_string: public function rollback() {
  		$this->txStatus = self::TX_NOT_STARTED;
  		$this->txCounter = 0;
  		return $this->driver->rollback();
  	}
code: public function rollback() {
  		$this->txStatus = self::TX_NOT_STARTED;
  		$this->txCounter = 0;
  		return $this->driver->rollback();
  	}
code_tokens: public function rollback ( ) { $ this -> txStatus = self :: TX_NOT_STARTED ; $ this -> txCounter = 0 ; return $ this -> driver -> rollback ( ) ; }
docstring: Rollbacks current transaction
docstring_tokens: Rollbacks current transaction