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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 cancel(self, order_ref):
 """Cancels an ongoing sign or auth order. This is typically used if the user cancels the order in your service or app. :param order_ref: The UUID string specifying which order to cancel. :type order_ref: str :return: Boolean regarding success of cancellation. :rtype: bool :raises BankIDError: raises a subclass of this error when error has been returned from server. """

        response = self.client.post(self._cancel_endpoint, json={"orderRef": order_ref})

        if response.status_code == 200:
            return response.json() == {}
        else:
            raise get_json_error_class(response)