Checks if the token file exists at the given position

        :return: if file exists or not
        :rtype: bool

def check_token_file(self):
        """ Checks if the token file exists at the given position

        :return: if file exists or not
        :rtype: bool
        """
        # 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