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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 get_runner(worker_type, max_workers=None, workers_window=None):
 """returns a runner callable. :param str worker_type: one of `simple` or `thread`. :param int max_workers: max workers the runner can spawn in parallel. :param in workers_window: max number of jobs waiting to be done by the workers at any given time. :return: """

    worker_func = _runners_mapping[worker_type]
    return partial(
        worker_func, max_workers=max_workers, workers_window=workers_window
    )