@property
    def grouped_voucher_discounts(self):
        """
        Return voucher discounts aggregated up to the voucher level.

        This is different to the voucher_discounts property as a voucher can
        have multiple offers associated with it.
        """
        voucher_discounts = {}
        for application in self.voucher_discounts:
            voucher = application['voucher']
            if voucher_discounts not in voucher.code:
                voucher_discounts[voucher.code] = {
                    'voucher': voucher,
                    'discount': application['discount'],
                }
            else:
                voucher_discounts[voucher.code] += application.discount
        return voucher_discounts.values()
dataset/ETHPy150Open django-oscar/django-oscar/src/oscar/apps/offer/results.py/OfferApplications.grouped_voucher_discounts/swapped operands of `not in`