code: def check_token_file(self):
          
          # TODO: remove this method in a future release
          warnings.warn('This method will be removed in future versions',
                        DeprecationWarning)
          return self.token_backend.check_token() if hasattr(self.token_backend, 'check_token') else None
docs: Checks if the token file exists at the given position
  
          :return: if file exists or not
          :rtype: bool