How to use the pyflink.common.restart_strategy.RestartStrategies._from_j_restart_strategy function in pyflink

def get_restart_strategy(self):
        """
        Returns the restart strategy which has been set for the current job.

        .. seealso:: :func:`set_restart_strategy`

        :return: The specified restart configuration.
        """
        return RestartStrategies._from_j_restart_strategy(
            self._j_execution_config.getRestartStrategy())

def get_restart_strategy(self):
        """
        Returns the specified restart strategy configuration.

        :return: The restart strategy configuration to be used.
        """
        return RestartStrategies._from_j_restart_strategy(
            self._j_execution_environment.getRestartStrategy())

def get_restart_strategy(self):
        """
        Returns the specified restart strategy configuration.

        :return: The restart strategy configuration to be used.
        """
        return RestartStrategies._from_j_restart_strategy(
            self._j_stream_execution_environment.getRestartStrategy())