def get_log_file(self, api=None):
        """
        Retrieve automation run log.
        :param api: sevenbridges Api instance
        :return: Log string
        """
        api = api or self._API
        log_file_data = self.execution_details.get('log_file')
        return File(api=api, **log_file_data) if log_file_data else None