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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 do_get_dataset(data, key, create=False):
 """Get a dataset. Parameters data : `None` or `dict` of `dict` of ([`int`, `str`] or [`list` of `int`, `list` of `str`]) Data. key : `str` Dataset key. create : `bool`, optional Create a dataset if it does not exist. Returns ------- `None` or `dict` of ([`int`, `str`] or [`list` of `int`, `list` of `str`]) """

        if data is None:
            return None
        try:
            return data[key]
        except KeyError:
            if create:
                dataset = {}
                data[key] = dataset
                return dataset
            else:
                raise