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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def worker(workers):
 """Starts a Superset worker for async SQL query execution."""

    logging.info(
        "The 'superset worker' command is deprecated. Please use the 'celery "
        "worker' command instead.")
    if workers:
        celery_app.conf.update(CELERYD_CONCURRENCY=workers)
    elif config.get('SUPERSET_CELERY_WORKERS'):
        celery_app.conf.update(
            CELERYD_CONCURRENCY=config.get('SUPERSET_CELERY_WORKERS'))

    worker = celery_app.Worker(optimization='fair')
    worker.start()