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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 order_by(self, order_by: Union[set, str]):
 """Update order_by setting for filter set"""

        clone = self._clone()
        if isinstance(order_by, str):
            order_by = {order_by}

        clone._order_by = clone._order_by.union(order_by)

        return clone