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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 all_subclasses(cls):
 """ Given a class `cls`, this recursive function returns a list with all subclasses, subclasses of subclasses, and so on. """

    subclasses = cls.__subclasses__() 
    return subclasses + [g for s in subclasses for g in all_subclasses(s)]