Push an error message to the driver to be printed in the background.

    Args:
        worker: The worker to use.
        error_type (str): The type of the error.
        message (str): The message that will be printed in the background
            on the driver.
        driver_id: The ID of the driver to push the error message to. If this
            is None, then the message will be pushed to all drivers.

def push_error_to_driver(worker, error_type, message, driver_id=None):
    """Push an error message to the driver to be printed in the background.

    Args:
        worker: The worker to use.
        error_type (str): The type of the error.
        message (str): The message that will be printed in the background
            on the driver.
        driver_id: The ID of the driver to push the error message to. If this
            is None, then the message will be pushed to all drivers.
    """
    if driver_id is None:
        driver_id = ray.DriverID.nil()
    worker.raylet_client.push_error(driver_id, error_type, message,
                                    time.time())