How to use the pyqs.worker.BaseWorker function in pyqs

def test_parent_process_death(os):
    """
    Test worker processes recognize parent process death
    """
    os.getppid.return_value = 123

    worker = BaseWorker(parent_id=1)
    worker.parent_is_alive().should.be.false

def test_parent_process_alive(os):
    """
    Test worker processes recognize when parent process is alive
    """
    os.getppid.return_value = 1234

    worker = BaseWorker(parent_id=1234)
    worker.parent_is_alive().should.be.true

packed_message, True, self.visibility_timeout)
            except Full:
                msg = (
                    "Timed out trying to add the following message "
                    "to the internal queue after {} seconds: {}"
                ).format(self.visibility_timeout, message_body)  # noqa
                logger.warning(msg)
                continue
            else:
                logger.debug(
                    "Message successfully added to internal queue "
                    "from SQS queue {} with body: {}".format(
                        self.queue_url, message_body))  # noqa


class ProcessWorker(BaseWorker):

    def __init__(self, internal_queue, interval, connection_args=None, *args,
                 **kwargs):
        super(ProcessWorker, self).__init__(*args, **kwargs)
        if connection_args is None:
            self.conn = get_conn()
        else:
            self.conn = get_conn(**connection_args)
        self.internal_queue = internal_queue
        self.interval = interval
        self._messages_to_process_before_shutdown = 100

    def run(self):
        # Set the child process to not receive any keyboard interrupts
        signal.signal(signal.SIGINT, signal.SIG_IGN)

def __init__(self, *args, **kwargs):
        self.parent_id = kwargs.pop('parent_id')
        super(BaseWorker, self).__init__(*args, **kwargs)
        self.should_exit = Event()

def shutdown(self):
        logger.info(
            "Received shutdown signal, shutting down PID {}!".format(
                os.getpid()))
        self.should_exit.set()

    def parent_is_alive(self):
        if os.getppid() != self.parent_id:
            logger.info(
                "Parent process has gone away, exiting process {}!".format(
                    os.getpid()))
            return False
        return True


class ReadWorker(BaseWorker):

    def __init__(self, queue_url, internal_queue, batchsize,
                 connection_args=None, *args, **kwargs):
        super(ReadWorker, self).__init__(*args, **kwargs)
        if connection_args is None:
            connection_args = {}
        self.connection_args = connection_args
        self.conn = get_conn(**self.connection_args)
        self.queue_url = queue_url

        sqs_queue = self.conn.get_queue_attributes(
            QueueUrl=queue_url, AttributeNames=['All'])['Attributes']
        self.visibility_timeout = int(sqs_queue['VisibilityTimeout'])

        self.internal_queue = internal_queue
        self.batchsize = batchsize