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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 meta_data_hash(self, obj_hash=None):
 """Creates a hash with the meta data of the model :param obj_hash: The hash object (see Python hashlib) :return: The updated hash object """

        if obj_hash is None:
            obj_hash = hashlib.sha256()
        self.update_meta_data_hash(obj_hash)
        return obj_hash