:param curve_rates:
        :return:

def curve_rates(self, curve_rates):
        """
        :param curve_rates:
        :return:
        """
        if curve_rates is not None:
            if isinstance(curve_rates, str):
                self._curve_rates = curve_rates
            else:
                try:
                    self._curve_rates = json.dumps(curve_rates)
                except TypeError:
                    raise TypeError('Passed in curve rates object are not json serializable.Please check the format')