original_string: protected function performRollBack($toLevel)
      {
          if ($toLevel === 0) {
              $this->getPdo()->rollBack();
          } elseif ($this->queryGrammar->supportsSavepoints()) {
              $this->getPdo()->exec(
                  $this->queryGrammar->compileSavepointRollBack('trans' . ($toLevel + 1))
              );
          }
      }
code: protected function performRollBack($toLevel)
      {
          if ($toLevel === 0) {
              $this->getPdo()->rollBack();
          } elseif ($this->queryGrammar->supportsSavepoints()) {
              $this->getPdo()->exec(
                  $this->queryGrammar->compileSavepointRollBack('trans' . ($toLevel + 1))
              );
          }
      }
code_tokens: protected function performRollBack ( $ toLevel ) { if ( $ toLevel === 0 ) { $ this -> getPdo ( ) -> rollBack ( ) ; } elseif ( $ this -> queryGrammar -> supportsSavepoints ( ) ) { $ this -> getPdo ( ) -> exec ( $ this -> queryGrammar -> compileSavepointRollBack ( 'trans' . ( $ toLevel + 1 ) ) ) ; } }
docstring: Perform a rollback within the database.
  
  @param int $toLevel
  
  @return void
docstring_tokens: Perform a rollback within the database .