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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, **kwargs):
 """ Analog to SQL "ORDER BY". +kwargs+ should only contain one item. examples) NO: repo.order_by() NO: repo.order_by(id="desc", name="asc") YES: repo.order_by(id="asc) """

        if kwargs:
            col, order = kwargs.popitem()
            self.order_clause = "order by {col} {order} ".format(
                col=col, order=order)
        return self