def METHOD_NAME(self, commit=True):
    instance = super().METHOD_NAME(commit)
    if commit:
        usage = self.cleaned_data["usage"]
        offers = self.cleaned_data["offers"]
        if instance is not None:
            # Update vouchers in this set
            for i, voucher in enumerate(instance.vouchers.order_by("date_created")):
                voucher.name = "%s - %d" % (instance.name, i + 1)
                voucher.usage = usage
                voucher.start_datetime = instance.start_datetime
                voucher.end_datetime = instance.end_datetime
                voucher.METHOD_NAME()
                voucher.offers.set(offers)
        # Add vouchers to this set
        vouchers_added = False
        for i in range(instance.vouchers.count(), instance.count):
            voucher = Voucher.objects.create(
                name="%s - %d" % (instance.name, i + 1),
                code=get_unused_code(length=instance.code_length),
                voucher_set=instance,
                usage=usage,
                start_datetime=instance.start_datetime,
                end_datetime=instance.end_datetime,
            )
            voucher.offers.add(*offers)
            vouchers_added = True
        if vouchers_added:
            instance.update_count()
    return instance