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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 register_action(*args, **kwarg):
    '''
    Decorator for an action, the arguments order is not relevant, but it's best
    to use the same order as in the docopt for clarity.
    '''
    def decorator(fun):
        KeywordArgumentParser._action_dict[frozenset(args)] = fun
        return fun
    return decorator